5. Parallel Lines and Triangles
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Use the Triangle Angle-Sum Theorem.
130-x
We have been given the measures of the two angles of a triangle, x and 50. We will find the measure of the third angle using the Triangle Angle-Sum Theorem.
This theorem tells us that the measures of the interior angles of a triangle must add to 180^(∘).
If we let y be the unknown measure of the third angle, we can create an equation to solve for the third angle.
The measure of the third angle is (130-x)^(∘).