Me really quick really confused 13 points!

The interior angles of a triangle all add up to 180°. In fact, for any n-sided polygon, the sum of the measures of the interior angles is 180°(n–2).

So, these three angles must add up to 180°.

That means, m∠A + m∠B + m∠C = 180°.

Substituting our known values, we write .

We then simplify this expression to solve for x. (Alternately, you could solve for m∠C first, but it's clearer to first solve for x.)



Then, to find m∠C, substitute 29° for x in  to get 93°.

(a) 29
(b) 93°