Answer:
x = 38
∠P = 26º
Step-by-step explanation:
The sum of the angle in a triangle is 180
x + (x + 78) + (x - 12) = 180
Combine like terms
3x + 66 = 180
Subtract 66 from both sides
3x = 114
Divide both sides by 3
x = 38
-----------------------
∠P = x - 12
∠P = 38 - 12
∠P = 26º
