Respuesta :
Answer:
50°
Step-by-step explanation:
The sum of angles in a triangle is 180 degrees
Hence given that in a triangle ACB with angles 90°, 4x°, 7x - 20
As such
90 + 4x + 7x -20 = 180
simplify
11x + 70 = 180
11x = 180 - 70
11x = 110
Divide both sides by 11
x = 110/11
x = 10
m∠ACB is 7x - 20
Substitute the value of x into the expression
= 7(10) - 20
= 70 - 20
= 50