Answer:
50 degrees
Explanation:
The sum of the interior angles of a triangle is 180. We can find the missing angle of the triangle by subtracting out the two measurement of the triangle that we know from 180.
180 - 31 -19 = 130
This angle would be the alternate exterior angel to the parallel line QP. That angle is supplement to the angle that you are looking for. <QTP would be 50 (180 -130)