Answer: a = 68°, b = 112°, c = 68°
Explanation:
There is an angle on your drawing that is referenced with an arc and a tic mark drawn through the arc. Let's call this angle "x".
On the left side of the graph, 112° and x are congruent (equal) because they are Vertical Angles. x = 112°
Notice that angle x is also on the right side of the graph.
a and x form a Linear Pair so they are supplementary angles (their sum equals 180°). a + x = 180 ⇒ a + 112 = 180 ⇒ a = 68°
b and x are congruent because they are Vertical Angles. So, b = 112°
a and c are congruent because they are Vertical Angles. So, c = 68°