Illustration showing a circle with a diameter, radius, lines, triangle, and segment drawn.

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…

Illustration of a circle with equal chords, which are equally distant from the center.

An illustration showing how to find the center of a circle which will pass through three given points…

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

Illustration of hexagon inscribed in circle. Or, circle circumscribed about hexagon.

Illustration of a circle with an angle inscribed in a segment greater than a semicircle, an acute angle.

Illustration of a circle with an angle inscribed in a segment less than a semicircle, an obtuse angle.

Illustration showing the diameter of a circle inscribed in a right triangle is equal to the difference…

Illustration of a circle with a right angle inscribed in a semicircle.

Illustration showing a circle with equilateral triangles and another circle within.

"A circle may be conceived as a polygon of an infinite number of sides. Thus to draw the involute of…

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

Illustration of pentagon inscribed in circle. Or, circle circumscribed about pentagon.

"If from any point on the circumference of a circle, a perpendicular be let fall upon a given diameter,…

Illustration of polygon circumscribed about circle. Or, circle inscribed in the polygon.

Illustration of polygon inscribed in circle. Or, circle circumscribed about the polygon.

Illustration of a quadrilateral circumscribed about a circle. This could also be described as a circle…

An illustration showing a quadrilateral inscribed in a circle that is tangent to a line.

Illustration of circle with radius of 4000, and triangle with 45 degree angle enclosed.

An illustration showing a circle with radius r, diameter d, and chord c.

A design created by dividing a circle into 4 equal arcs and reflecting each arc toward the center of…

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…

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…

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…

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…

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…

Illustrations of a circle with secant AD and line BC tangent to it.

Illustration of circle with sector and segment used to find area.

Illustration of partial circle with sector and segment used to find area.

Illustration of a sector of a circle. A sector is the space between an arc and two radii drawn to the…

Illustration of a sector of a hollow circle. A sector is the space between an arc and two radii drawn…

Illustration of circle with diameter and segment used to find area.

Illustrations of a circle with segment, semicircle, sector, quadrant, and central angles drawn.

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…

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…

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…

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…

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…

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.…