Prove that the triangle EDF is isosceles.
Give reasons for your answer.

Answer:
y + 180/2
Step-by-step explanation:
90 + y/2
2 x 90 + y/2
2 x 90/2 + y/2
2 x 90 + y/2
2 x 90 + y/2
180 + y/2
180 + y/2
y + 180/ 2
y + 180/2