Lesson: Isosceles Triangle Theorems Mathematics • 11th Grade

Students will be able to

• label the sides of an isosceles triangle as the legs and the base,
• label the angles of an isosceles triangle as the base angles and the vertex angle,
• prove that the base angles of an isosceles triangle are equal and use this to find missing angles,
• prove that if two angles of a triangle are congruent, then their opposite sides are congruent and the triangle is an isosceles triangle and use this to solve problems,
• use the isosceles triangle theorems to identify whether a triangle is isosceles.