In the adjoining figure, GP bisects angle BGH and HP bisects angle GHD. calculate the size of angle a.

Answer:
90°
Step-by-step explanation:
AB and CD are parallel lines and EF is reversal
Therefore angles BGH and DHG are consecutive interior angles
As we know the sum of consecutive interior angles equals to 180°:
Line GP bisects angle BGH , therefore
Line HP bisects angle GHD, therefore
Sum of two angles of triangle GHP:
Therefore the missing angle a is: