Find the value of x in the following figures.

According to theorem that the angle which is subtended by an arc at the centre of a circle is double the size of the angle subtended at any point on the circumference.

∠AOB = 2 × 25 = 50°

∠AOC = 2 × 30 = 60°

At centre O

∠AOB + ∠AOC + x° = 360°

x = 360–60–50 = 250°