Respuesta :

30° + 2x = 180°

2x = 180° - 30°

2x = 150°

x = 150° : 2

x = 75° (A)

Answer:

A. 77

Step-by-step explanation:

This is an isosceles triangle, if the top angle is 30 then the other two angles' sum is 150 and equal to each other so the answer is 75.