Question

In the given figure ,chord AB subtends an angle of 60° at the centre of the circle. If OA=5cm,then find the length of AB.​

Answer 1

Step-by-step explanation:

OA=OB(both are radii of same circle)

∠OAB=∠OBA=x(say)

In ΔAOB,

∠OBA+∠OAB+∠AOB=180°

x+x+60°=180°

2x+60°=180°⇒2x=180°-60°=120°⇒x=120/2=60°

∠OAB=∠OBA=∠AOB=60°

∴ΔAOB is equilateral

AB=OA=5cm

∴AB=5cm