A) 60
B) 120
C) 30
D) 90

Answer:
The answer would be B) 120
Step-by-step explanation:
In the triangle with angle 2 and 3, it has a right angle in it, making angle 2 and 3 added together 90 degrees. But you have to figure out what angle 2 and 3 equal. Well the whole triangle is equilateral, making all three angles equal to 60 degrees. Angle 3 is half of 60 degrees because it is split by the dotted line. This makes angle 3 equal to 30 degrees. Now you can find the measure of angle 2. 30(angle 3) plus 90(right angle) equals 120 degrees. This makes angle 2 equal to 60 degrees. In this image, angle 2 is half of angle 1. So angle one is equal to 120 degrees. I hope this helps.