Question

In an isosceles triangle, one of the base angles is 80°. What is the value of the vertical angle?

a. 40°
b. 50°
c. 80°
d. 100°

Answer 1

In an isosceles triangle, if one of the base angles is 80°, the value of the vertical angle is 20°.

Step-by-step explanation:

An isosceles triangle has two equal base angles. If one of the base angles is 80°, then the other base angle is also 80°. The sum of the angles in a triangle is always 180°. Therefore, the value of the vertical angle is 180° - 80° - 80° = 20°.