Answer:
∠B = 37°
Explanation:
The sum of the 3 angles in a triangle = 180°
Sum the 3 given angles and equate to 180
2x + 15 + 5x - 2 + 90 = 180, that is
7x + 103 = 180 ( subtract 103 from both sides )
7x = 77 ( divide both sides by 7 )
x = 11
Hence
∠B = 2x + 15 = (2 × 11) + 15 = 22 + 15 = 37°