
The congruent sides of an isosceles triangle are called ______________.
legs

The non congruent side of an isosceles triangle is called the _______________.
base

The two angles at the base of an isosceles triangle are called the _________________.
sides

If two angles at the base of an isosceles triangle congruent, then _______________________.
the angles opposite them are congruent.

If two angles of a triangle are congruent, then ________________________________.
the sides opposite them are congruent.

If a triangle is equilateral, then it is __________.
equilangular

If a triangle is equiangular, then it is ____________ .
equilateral

Theorem 41
The Isosceles Triangle Theorem
If two sides of a triangle are congruent, then the angles opposite those sides are congruent.

The Isosceles Triangle Theorem (Theorem 41) often stated that the base angles of an isosceles triangle are congruent.
* An equilateral triangle is also equiangular.
* An equilateral triangle has three 60° angles.
* The bisector of the vertex angles of an isosceles triangle is perpendicular to the base at its midpoint.

Theorem 42
If two angles of a triangle are congruent, then the sides opposite those angles are congruent.
Corollary
An equiangular triangle is also equilateral.






Find interior and exterior angle sum

Find each interior and exterior angle in regular polygons

Find missing interior and exterior angles in irregular polygons

Differentiate between convex and nonconvex polygons


