Question

PLEASE answer the question fast...​

Answer 1

Step-by-step explanation:

Extend AD to F on side BC.

Then, in ΔFAB

Exterior angle ∠CFA=α˚+β˚

In ΔFCD

Exterior angle ∠ADC=∠FCD+∠CFA

So, x = γ˚+α˚+β˚

HENCE PROVED