Find the unknown angle

77 degrees

Step-by-step explanation:

Right triangles always add up to 180 degrees. We know that one angle is 23 degrees, angle A is missing, and the last angle is a right angle which is equal to 90 degrees. Knowing what we know, we must subtract the two known angles from 180 to get angle A.

180 - 90 = 90

90 - 23 = 77

Angle A is equal to 77 degrees.

hope this helps!! :]

a = 11 : 4

b = 38

c = 1 for every 6