Radius of a circle is 18 cm. Angle made by chord AB at the centre of this circle is 60°. What is the length of this chord?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 18 cm.
OA = OB = 18 cm
ΔOAB is an isosceles triangle.
So, ∠OAB = ∠OBA = (180° - 60°)/2 = 60°
∠OAB = ∠OBA = ∠OAB = 60°
So ΔOAB is an equilateral triangle.
OA = OB = AB = 18 cm
Hence, the length of this chord is 18 cm.