Question

What is the measure of the vertex angle of an isosceles triangle if one of its base angles measures 73° and its congruent sides each measure 15 cm?

Answer 1

73+73=146
180-146= 34
The vertex angle is 34

Answer 2

The measure of the vertex angle will be 34°

Explanation:

As isosceles triangle have two equals sides and two equals angle. The two equals angle are the base angles b. We know that the sum of the angle of a triangle is 180°:

v+b+b=180°

v+2b=180°

Where v is the vertex angle. If we know the value of the base angles is 73° then the remaing vertex angle will be calculated by solving for a in the equation above:

v=180°-2*73°

v=180°-146°=34°