Answer:
E) 45
Step-by-step explanation:
Since b is 90 degrees, and lines CB and BA are equal (as seeen with the 2 lines across them) we can assume that this angle is 45 degrees, half or 90 degrees.
Angle C is also equal to angle A
E
Using the fact that the sum of angles in a triangle is 180 degrees, we can write the following equation to solve for 3x:
3x + 3x + 90 = 180
3x + 3x = 90
2 * 3x = 90
3x = 45°
