Geometry · Triangles & Congruence
Equilateral Triangle
HSG-CO.C.10
Definition
A triangle with three congruent sides and three 60 degree angles.
Examples
- An equilateral triangle has three 60 degree angles: 60 x 3 = 180.
- All three sides of an equilateral triangle are equal in length.
Key rule
Every equilateral triangle is also isosceles, but not every isosceles triangle is equilateral.
Memory hook
All equal — sides and angles alike.