In an isosceles triangle, the base angles are equal. The vertex angle is 40°.

Question

Solve the following :

In an isosceles triangle, the base angles are equal. The vertex angle is 40°. What are the base angles of the triangle ? (Re-member, the sum of three angles of a triangle is 180°).

Answer 1

Let the base angles of an isosceles triangle be x°
According to the question
2x° + 40° = 180°
2x° = 180° – 40°
2x°= 140

The base angles are 70° and 70°