you subtract the ones that give you the exterior angle by 180 because it is a supplementary angle. that means that both angles add up to 180. the little square next to angle three means its a right angle. this means it is exactly 90°. the last angle is a little tricky. you need to add up all the angles you have and then you if you get 540 then your answer is correct because all interior angles of a pentagon must add up to 540.
Hope you have a great day and I hope this helped you out!
