Question:
In the given figure, O is the centre of a circle and ∠BOD = 150°. Find the values of x and y.
Solution:
O is the centre of the circle and ∠BOD = 150°.
Thus, reflex angle ∠BOD = (360° – 150°) = 210°
Now, $x=\frac{1}{2}(\operatorname{reflex} \angle B O D)=\left(\frac{1}{2} \times 210^{\circ}\right)=105^{\circ}$
∴ x = 105°
Again, x + y = 180° (Opposite angles of a cyclic quadrilateral)
⇒ 105° + y = 180°
⇒ y = (108° - 105°)= 75°
∴ y = 75°
Hence, x = 105° and y = 75°