Answer:
m∠P = 107º
Step-by-step explanation:
Since two sides are parallel this is a trapezoid
In a trapezoid, the angles on the same leg (called adjacent angles) are supplementary, meaning they add up to 180 degrees.
(7x + 31) + (21x - 19) = 180
combine like terms
28x + 12 = 180
Subtract 12 from both sides
28x = 168
Divide both sidees by 28
x = 6
m∠P = 21x - 19
m∠P = 21(6) - 19
m∠P = 107º
