Answer:
x = 12
The sum of ∠A and ∠C is 90°.
Explanation:
Interior angles of a triangle sum to 180°.

From inspection of the given right triangle:
- m∠A = (2x + 1)°
- m∠B = 90°
- m∠C = (5x + 5)°
Substitute the given angles into the equation and solve for x:











Therefore, the value of x is 12.
To find the measure of each angle, substitute the found value of x into the expression for each angle: