Answer the following:

Question

1. ∆ABC is isosceles with base AC. If m∠A = 40, what is m∠B and m∠C? If BA = 10 cm, what is BC?
2. If ∆DEF is equilateral, what is the measure of each angle?
3. If the perimeter of an equiangular triangle is 60 cm, what is the measure of each side?
4. In isosceles ∆ GHI, vertex angle measures 50, what is the measure of each base angle?
5. ∆ ABC is isosceles with base AC. If AC = x, AB = 2x, and the perimeter is 55, what is BC?

Answer 1

To answer these questions you need the following information:

In an isosceles triangle 2 sides are equal and the angles opposite these sides are equal.

The sum of the angles of a triangle is 180 degrees.

In an equilateral triangle all 3 sides are equal and all the angles are equal.

Now think!