A line is tangent to a circle at point A. If a chord AB has a length of 8 cm and makes an angle of 30° with the tangent, what is the radius of the circle?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 8 cm.
At the point of tangency A, the radius is perpendicular to the tangent.
The chord AB makes an angle of 30° with the tangent, so ∠OAB = 90° – 30° = 60°
In ΔOAB, OA = OB = radius, and ∠OAB = 60°
So triangle OAB is equilateral.
AB = radius = 8 cm