Illustration of a decagon circumscribed about a circle. This can also be described as a circle inscribed in a decagon.

Decagon Circumscribed About A Circle

Illustration of a decagon circumscribed about a circle. This can also be described as a circle inscribed…

Illustration of a decagon inscribed in a circle. This can also be described as a circle circumscribed about a decagon.

Decagon Inscribed In A Circle

Illustration of a decagon inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a dodecagon circumscribed about a circle. This can also be described as a circle inscribed in a dodecagon.

Dodecagon Circumscribed About A Circle

Illustration of a dodecagon circumscribed about a circle. This can also be described as a circle inscribed…

Illustration of a dodecagon inscribed in a circle. This can also be described as a circle circumscribed about a dodecagon.

Dodecagon Inscribed In A Circle

Illustration of a dodecagon inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a hexagon in a circle. Four of the six vertices of the hexagon are bound by the circle (are tangent to the circle). Because all six vertices are not on the circle, the hexagon is not cyclic; it is not inscribed in the circle.

Hexagon In A Circle

Illustration of a hexagon in a circle. Four of the six vertices of the hexagon are bound by the circle…

Illustration of a regular heptagon/septagon inscribed in a circle. This can also be described as a circle circumscribed about a regular heptagon/septagon.

Regular Heptagon/Septagon Inscribed In A Circle

Illustration of a regular heptagon/septagon inscribed in a circle. This can also be described as a circle…

Illustration of a regular hexagon circumscribed about a circle. This can also be described as a circle inscribed in a regular hexagon.

Regular Hexagon Circumscribed About A Circle

Illustration of a regular hexagon circumscribed about a circle. This can also be described as a circle…

Illustration of a regular hexagon inscribed in a circle. This can also be described as a circle circumscribed about a regular hexagon.

Regular Hexagon Inscribed In A Circle

Illustration of a regular hexagon inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a regular hexagon inscribed in a circle. This can also be described as a circle circumscribed about a regular hexagon. All diagonals of the hexagon are also diameters of the circle. The diagonals intersect at the center of both the hexagon and the circle.

Regular Hexagon Inscribed In A Circle

Illustration of a regular hexagon inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a regular nonagon circumscribed about a circle. This can also be described as a circle inscribed in a regular nonagon.

Regular Nonagon Circumscribed About A Circle

Illustration of a regular nonagon circumscribed about a circle. This can also be described as a circle…

Illustration of a regular nonagon inscribed in a circle. This can also be described as a circle circumscribed about a regular nonagon.

Regular Nonagon Inscribed In A Circle

Illustration of a regular nonagon inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a regular octagon circumscribed about a circle. This can also be described as a circle inscribed in a regular octagon.

Regular Octagon Circumscribed About A Circle

Illustration of a regular octagon circumscribed about a circle. This can also be described as a circle…

Illustration of a regular octagon inscribed in a circle. This can also be described as a circle circumscribed about a regular octagon.

Regular Octagon Inscribed In A Circle

Illustration of a regular octagon inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a regular pentagon circumscribed about a circle. This can also be described as a circle inscribed in a regular pentagon.

Regular Pentagon Circumscribed About A Circle

Illustration of a regular pentagon circumscribed about a circle. This can also be described as a circle…

Illustration of a regular pentagon inscribed in a circle. This can also be described as a circle circumscribed about a regular pentagon.

Regular Pentagon Inscribed In A Circle

Illustration of a regular pentagon inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a square, with diagonals drawn, circumscribed about a circle. This can also be described as a circle inscribed in a square. The diagonals of the square intersect at the center of both the square and the circle. The diagonals coincide with the diameter of the circle.

Square Circumscribed About A Circle

Illustration of a square, with diagonals drawn, circumscribed about a circle. This can also be described…

Illustration of a square, with 1 diagonals drawn, circumscribed about a circle. This can also be described as a circle inscribed in a square. The diagonal goes through the center of both the square and the circle and coincides with the diameter of the circle.

Square Circumscribed About A Circle

Illustration of a square, with 1 diagonals drawn, circumscribed about a circle. This can also be described…

Illustration of a square circumscribed about a circle. This can also be described as a circle inscribed in a square.

Square Circumscribed About A Circle

Illustration of a square circumscribed about a circle. This can also be described as a circle inscribed…

Illustration of a square inscribed in a circle. This can also be described as a circle circumscribed about a square.

Square Inscribed In A Circle

Illustration of a square inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a square inscribed in a circle. This can also be described as a circle circumscribed about a square. The diagonal of the square is also the diameter of the circle.

Square Inscribed In A Circle

Illustration of a square inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a square, with diagonals drawn, inscribed in a circle. This can also be described as a circle circumscribed about a square. The diagonals, which are also the diameter of the circle, intersect at the center of both the square and the circle.

Square Inscribed In A Circle

Illustration of a square, with diagonals drawn, inscribed in a circle. This can also be described as…

Illustration of a 6-point star (convex dodecagon) circumscribed about a circle. This can also be described as a circle inscribed in a 6-point star, or convex dodecagon.

Star Circumscribed About A Circle

Illustration of a 6-point star (convex dodecagon) circumscribed about a circle. This can also be described…

Illustration of an 8-point star (convex polygon) circumscribed about a circle. This can also be described as a circle inscribed in an 8-point star, or convex polygon.

Star Circumscribed About A Circle

Illustration of an 8-point star (convex polygon) circumscribed about a circle. This can also be described…

Illustration of a 5-point star inscribed in a circle. This can also be described as a circle circumscribed about a 5-point star.

Star Inscribed In A Circle

Illustration of a 5-point star inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a 6-point star created by two equilateral triangles (often described as the Star of David) inscribed in a circle. This can also be described as a circle circumscribed about a 6-point star, or two triangles.

Star Inscribed In A Circle

Illustration of a 6-point star created by two equilateral triangles (often described as the Star of…

Illustration of a 6-point star (convex dodecagon) inscribed in a circle. This can also be described as a circle circumscribed about a 6-point star, or convex dodecagon.

Star Inscribed In A Circle

Illustration of a 6-point star (convex dodecagon) inscribed in a circle. This can also be described…

Illustration of an 8-point star, created by two squares at 45° rotations, inscribed in a circle. This can also be described as a circle circumscribed about an 8-point star, or two squares.

Star Inscribed In A Circle

Illustration of an 8-point star, created by two squares at 45° rotations, inscribed in a circle.…

Illustration of an 8-point star, or convex polygon, inscribed in a circle. This can also be described as a circle circumscribed about an 8-point star.

Star Inscribed In A Circle

Illustration of an 8-point star, or convex polygon, inscribed in a circle. This can also be described…

Illustration of an equilateral triangle circumscribed about a circle. This can also be described as a circle inscribed in an equilateral triangle.

Triangle Circumscribed About A Circle

Illustration of an equilateral triangle circumscribed about a circle. This can also be described as…

Illustration of an equilateral triangle inscribed in a circle. This can also be described as a circle circumscribed about an equilateral triangle.

Triangle Inscribed In A Circle

Illustration of an equilateral triangle inscribed in a circle. This can also be described as a circle…

2 congruent circles whose intersection includes a tangent circle with diameter equal to the radii of the larger circles.

2 Intersecting Circles

2 congruent circles whose intersection includes a tangent circle with diameter equal to the radii of…

A large circle containing 3 smaller congruent circles. The small circles are externally tangent to each other and internally tangent to the larger circle.

3 Smaller Circles In A Larger Circle

A large circle containing 3 smaller congruent circles. The small circles are externally tangent to each…

A large circle containing 3 smaller congruent circles. The small circles are externally tangent to each other and internally tangent to the larger circle.

3 Smaller Circles In A Larger Circle

A large circle containing 3 smaller congruent circles. The small circles are externally tangent to each…

A large circle containing 4 smaller congruent circles. The small circles are externally tangent to each other and internally tangent to the larger circle.

4 Smaller Circles In A Larger Circle

A large circle containing 4 smaller congruent circles. The small circles are externally tangent to each…

A large circle containing 4 smaller congruent circles. The small circles are externally tangent to each other and internally tangent to the larger circle.

4 Smaller Circles In A Larger Circle

A large circle containing 4 smaller congruent circles. The small circles are externally tangent to each…

A sequence of five circles tangent to each other at a point. The radius decreases by one half in each successive circle.

5 Tangent Circles

A sequence of five circles tangent to each other at a point. The radius decreases by one half in each…

A regular hexagon containing 7 congruent circles. The circles are externally tangent to each other and internally tangent to the hexagon.

7 Congruent Circles In A Regular Hexagon

A regular hexagon containing 7 congruent circles. The circles are externally tangent to each other and…

A large circle containing 7 smaller congruent circles. The small circles are externally tangent to each other and internally tangent to the larger circle.

7 Smaller Circles In A Larger

A large circle containing 7 smaller congruent circles. The small circles are externally tangent to each…

A large circle containing 7 smaller congruent circles. The small circles are externally tangent to each other and internally tangent to the larger circle.

7 Smaller Circles In A Larger Circle

A large circle containing 7 smaller congruent circles. The small circles are externally tangent to each…

7 congruent circles. 6 of the circles are equally placed about the center circle. The circles are externally tangent to each other.

7 Tangent Circles

7 congruent circles. 6 of the circles are equally placed about the center circle. The circles are externally…

An illustration depicting an infinite sequence of tangent circles with the radius converging to zero. This is often called a Hawaiian earring.

Infinite Tangent Circles

An illustration depicting an infinite sequence of tangent circles with the radius converging to zero.…

Illustration of a 6-point star (convex dodecagon) inscribed in a large circle and circumscribed about a smaller circle.

Star Inscribed And Circumscribed About Circles

Illustration of a 6-point star (convex dodecagon) inscribed in a large circle and circumscribed about…

Illustration of an 8-point star (convex polygon) inscribed in a large circle and circumscribed about a smaller circle.

Star Inscribed And Circumscribed About Circles

Illustration of an 8-point star (convex polygon) inscribed in a large circle and circumscribed about…

A large cylinder containing 2 smaller congruent cylinders. The small cylinders are externally tangent to each other and internally tangent to the larger cylinder.

2 Smaller Cylinders In A Larger Cylinder

A large cylinder containing 2 smaller congruent cylinders. The small cylinders are externally tangent…

A large cylinder containing 3 smaller congruent cylinders. The small cylinders are externally tangent to each other and internally tangent to the larger cylinder.

3 Smaller Cylinders In A Larger Cylinder

A large cylinder containing 3 smaller congruent cylinders. The small cylinders are externally tangent…

A large cylinder containing 4 smaller congruent cylinders. The small cylinders are externally tangent to each other and internally tangent to the larger cylinder.

4 Smaller Cylinders In A Larger Cylinder

A large cylinder containing 4 smaller congruent cylinders. The small cylinders are externally tangent…

Illustration of 4 congruent cylinders with diameters less than the height. The cylinders are externally tangent to each other.

4 Tangent Cylinders

Illustration of 4 congruent cylinders with diameters less than the height. The cylinders are externally…

A large cylinder containing 7 smaller congruent cylinders. The small cylinders are externally tangent to each other and internally tangent to the larger cylinder.

7 Smaller Cylinders In A Larger Cylinder

A large cylinder containing 7 smaller congruent cylinders. The small cylinders are externally tangent…

Illustration of 7 congruent cylinders with diameters less than the height. 6 of the cylinders are equally placed about the center cylinder. The cylinders are externally tangent to each other.

7 Tangent Cylinders

Illustration of 7 congruent cylinders with diameters less than the height. 6 of the cylinders are equally…

Illustration of 7 congruent cylinders with diameters less than the height. 6 of the cylinders are equally placed about the center cylinder. The cylinders are externally tangent to each other.

7 Tangent Cylinders

Illustration of 7 congruent cylinders with diameters less than the height. 6 of the cylinders are equally…

Illustration of a 12-point star (24-sided polygon) inscribed in a regular dodecagon. This can also be described as a regular dodecagon circumscribed about a 12-point star (24-sided polygon).

12-Point Star Inscribed In A Dodecagon

Illustration of a 12-point star (24-sided polygon) inscribed in a regular dodecagon. This can also be…

Illustration of a cyclic hexagon, a hexagon inscribed in a circle. This can also be described as a circle circumscribed about a hexagon. In this illustration, the hexagon is not regular (the lengths of the sides are not equal).

Cyclic Hexagon

Illustration of a cyclic hexagon, a hexagon inscribed in a circle. This can also be described as a circle…

Illustration of a cyclic hexagon, a hexagon inscribed in a circle. This can also be described as a circle circumscribed about a hexagon. In this illustration, the hexagon is not regular (the lengths of the sides are not equal).

Cyclic Hexagon

Illustration of a cyclic hexagon, a hexagon inscribed in a circle. This can also be described as a circle…

Illustration of a cyclic pentagon, a pentagon inscribed in a circle. This can also be described as a circle circumscribed about a pentagon. In this illustration, the pentagon is not regular (the lengths of the sides are not equal).

Cyclic Pentagon

Illustration of a cyclic pentagon, a pentagon inscribed in a circle. This can also be described as a…

Illustration of a cyclic quadrilateral, a quadrilateral inscribed in a circle. This can also be described as a circle circumscribed about a quadrilateral. In this illustration, the quadrilateral is not regular (the lengths of the sides are not equal).

Cyclic Quadrilateral

Illustration of a cyclic quadrilateral, a quadrilateral inscribed in a circle. This can also be described…

Illustration of a regular heptagon/septagon circumscribed about a circle. This can also be described as a circle inscribed in a regular heptagon/septagon.

Regular Heptagon/Septagon Circumscribed about a Circle

Illustration of a regular heptagon/septagon circumscribed about a circle. This can also be described…