Describing Triangles

We see in the diagram that the triangle is equilateral. If a triangle is equilateral, then it is also equiangular. This means that all three angles have the same measure.

According to the interior angles theorem, the sum of the measures of the interior angles of a triangle is

180.

x+x+x=180

AddTermsAdd terms

3x=180

DivEqn

\left.\text{LHS}\middle/3\right.=\left.\text{RHS}\middle/3\right.

x=60

Describing Triangles 1.1 - Solution