Question

Questions number 15
Please answer fast....its urgent

Answer 1

To prove
ae equal a d
In triangle BeC
Angle a ECD is equal to angle BEC ( alternate angles)
therefore be =BC
or ae = ad ( as e is the mid point and BC=ad)


in triangle aed
AED is equal to EDC (alt. angle)
as ae =ad
angle aed=Ade
therefore Ade=edc
therefore de bisects angle ADC


angle Dec =180-(edc+ECD)/2
=180-(BCD+ACD)/2
180-180/2
90