An equilateral triangle fits into its outline three times in a full 360° turn. Image caption, An isosceles triangle has two sides that are equal in length. Isosceles means equal legs. The ‘legs ...

Isosceles triangle. An isosceles triangle is a triangle that has two equal sides and two equal angles. The two equal angles always occur where the third non equal side meets one of the equal sides.

Plus, Calter argues, the triangle has big fans. Plato declared the isosceles triangle to be the basic building block of the universe in his Theory of Everything. And, of course, there's the Holy ...

The famed proof of irrational numbers presented by Hippasus—or another Pythagorean—is most easily illustrated with an isosceles right triangle: consider a triangle with two sides, each of ...