Answer:
Angle A is 20°
Step-by-step explanation:
The sum of the interior angles of a triangle is 180°.
90 + 10x + x +13 = 180 Combine like terms
103 + 11x + 180 Subtract 103 from both sides
11x = 77 Divide both sides by 11
x = 7
Angle A is 13 + x. X is 7, so 13 + 7 = 20
