Question

find x,y,z?????????????

Answer 1

since AB=AD=> x= 70 degrees
(angles opposite to equal sides )
in triangle ACD, z=180-(100+70)=> 180-170
=> z=10 degrees
now angle ACB=> 180-100 (linear pair )
=> 80 degrees
therefore y =>180-(80+70)
=>180-150=>30 degrees

Answer 2

In ΔABD, 
It's given that AB=AD
⇒It is isosceles
∴∠B = x =70° ( isosceles triangle property)
∠B + z + y +x = 180° (Angle sum proptery)
 70°+70°+ y + z  = 180°
                  y + z = 180° - 140°
                ∴y + z = 40° →1
In ΔACD, 
  x + z + 100° = 180° (Angle sum property)
70°+100°+  z = 180° 
                   z = 180°-170°
            ∴ z=10°
 Substituting z in 1, we get:
            y+z=40°
           y+10°=40°
                y=40°-10°
            ∴y=30°