Answer: 56 degrees
Step-by-step explanation:
We know that angle between b and c is 90 degrees. Because there is a line dividing angles a and b from 124 and c, we also know that each side is 180 degrees (a and b add to 180, and 124 and c add to 180).
124 and c are supplementary angles. We can represent this in an equation to solve for c: