Illustration of three circles enclosed in an equilateral triangle.

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

An illustration of a pyramid with the top cut off by a plane parallel to the base. The remaining part…

(1828-1905) French author most famous for Twenty Thousand Leagues under the Sea, From the Earth to the…