what is the value of p (can someone explain how to solve these type of problems as well please, thank u!)

∠P = 35°

Step-by-step explanation:

One exterior angle is 90°. The adjacent angle must also be 90° because those two angles are supplementary angles, so they add up to 180°. Another exterior angle is 125°. The adjacent angle must be 55°, because the interior and exterior angles form a supplementary angle. Now we know that two of the angles are 90° and 55°. All of the angles in a triangle must add up to 180°. 90° + 55° = 145°. 180° - 145° = 35°. ∠P = 35°.

I hope this helps! It's all about interior and exterior angles and how they form supplementary angles.