Answer:
a. 30°
Explanation:
The geometric shape shown in the image is an isosceles triangle.
The top angle is 120 and the sum of interior angles in a triangle is equal to 180°.
The angles on the bottom (both legs) are equal, let x represent it so we can write the following equation:
120 + x + x = 180 add like terms
120 + 2x = 180 subtract 120 from both sides
2x = 60 divide both sides by 2
x = 30