Question

In the given circle with diameter AB, find the value of x.

Answer 1

∠ ABD = ∠ ACD = 30°       ....(∠s of same segment)
∠ADB = 90°                       ....(∠ in the semi circle)

In ΔADB,
x° + 90° + 30° = 180°       ....(Sum of all ∠s of triangle)
x° = 180° - 120°
x° = 60°.