Diagram used to prove the theorem: "Two trihedral angles, which have three face angles of the one equal…

Equal circles inside and tangent to the outside circle, also tangent to each other

Circular rosette-like pattern made with 12 overlapping congruent circles tangent to a center circle…

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

Circular rosette-like pattern made with 24 overlapping congruent circles tangent to a center circle…

Circular rosette-like pattern made with 48 overlapping congruent circles tangent to a center circle…

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

Illustration of 108 congruent cubes stacked at various heights. A 3-dimensional representation on a…

Illustration of 117 congruent cubes stacked in columns of one, four, and six. A 3-dimensional representation…

Illustration of 128 congruent cubes stacked so they form a rectangular solid that measures 4 by 4 by…

Illustration of 132 congruent cubes stacked in 22 columns of 6 in the shape of a U. A 3-dimensional…

Illustration of 154 congruent cubes stacked in columns increasing from one to four. A 3-dimensional…

Illustration of 16 congruent cubes stacked at various heights. A 3-dimensional representation on a 2-dimensional…

Illustration of 17 congruent cubes stacked in ones and twos in the shape of a V. A 3-dimensional representation…

Illustration of two congruent cubes that are tangent along an edge. A 3-dimensional representation on…

Illustration of 20 congruent cubes stacked in twos and threes. A 3-dimensional representation on a 2-dimensional…

Illustration of 20 congruent cubes stacked at various heights. A 3-dimensional representation on a 2-dimensional…

Illustration of 20 congruent cubes stacked at heights increasing from 1 to 4 cubes. A 3-dimensional…

Illustration of 22 congruent cubes stacked in ones, twos, and threes. A 3-dimensional representation…

Illustration of 22 congruent cubes stacked at various heights. A 3-dimensional representation on a 2-dimensional…

Illustration of 24 congruent cubes stacked at various heights to resemble steps. A 3-dimensional representation…

Illustration of 256 congruent cubes stacked so they form 4 larger cubes that measures 4 by 4 by 4 each.…

Illustration of 27 congruent cubes stacked to resemble a larger cube that measures three by three by…

Illustration of 27 congruent cubes stacked at various heights in the shape of a W. A 3-dimensional representation…

Illustration of 28 congruent cubes placed in the shape of a square. A 3-dimensional representation on…

Illustration of 30 congruent cubes stacked in decreasing heights. A 3-dimensional representation on…

Illustration of 33 congruent cubes stacked at various heights in a zigzag pattern. A 3-dimensional representation…

Illustration of 35 congruent cubes stacked in ones and twos in the shape of a W. A 3-dimensional representation…

Illustration of 35 congruent cubes stacked at various heights. A 3-dimensional representation on a 2-dimensional…

Illustration of 36 congruent cubes stacked at various heights with outer edges forming a square. A 3-dimensional…

Illustration of 36 congruent cubes stacked to resemble a 1 by 1 by 1 cube on a 2 by 2 by 2 cube on a…

Illustration of 39 congruent cubes stacked at various heights. A 3-dimensional representation on a 2-dimensional…

Illustration of 4 congruent cubes stacked in ones and twos. A 3-dimensional representation on a 2-dimensional…

Illustration of 50 congruent cubes stacked at various heights. A 3-dimensional representation on a 2-dimensional…

Illustration of 56 congruent cubes stacked in twos in the shape of a square. A 3-dimensional representation…

Illustration of 56 congruent cubes stacked in heights of 1, 4, and 5 cubes that form a zigzag pattern.…

Illustration of 57 congruent cubes stacked in heights of 1 and 5 cubes that form a zigzag pattern. A…

Illustration of 59 congruent cubes stacked at various heights. A 3-dimensional representation on a 2-dimensional…

Illustration of 64 congruent cubes stacked so they form a cube that measures 4 by 4 by 4. A 3-dimensional…

Illustration of 65 congruent cubes stacked at heights increasing from 1 to 5 cubes. A 3-dimensional…

Illustration of 3 right congruent tangent circular cylinders. The height of all the cylinders is greater…

Illustration of 3 right congruent tangent circular cylinders.

Illustration of 3 right congruent tangent circular cylinders. The height of all the cylinders is greater…

Illustration of 4 congruent tangent right circular cylinders. The height of all the cylinders is greater…

Illustration of 16 concentric congruent ellipses that are rotated about the center at equal intervals…

Illustration of 2 concentric congruent ellipses that are rotated about the center at 90°. The ellipses…

Illustration of 4 concentric congruent ellipses that are rotated about the center at equal intervals…

Illustration of 8 concentric congruent ellipses that are rotated about the center at equal intervals…

Illustration used to show how to construct an angle equal to a given angle when given a vertex and a…

Illustration used to show how to construct an equilateral triangle, with a given line as a side.

Illustration of 2 ladders leaning against opposite sides of a palm tree to form similar right triangles.…

Illustration used to prove the theorem "Two parallelograms are equal if two sides and the included angle…

Diagram used to prove the theorem: "The opposite faces of a parallelopiped are equal and parallel."

Diagram used to prove the theorem: "The rectangular parallelopipeds which have two dimensions in common…

Diagram used to prove the theorem: "The rectangular parallelopipeds are to each other as the product…

Illustration of 2 right octagonal prisms with congruent bases, but different heights. The height of…

Illustration of 2 Similar right octagonal prisms. The height and length of the edges of the smaller…