Multiple choice

The length of a chord of circle is 4 cm. If its perpendicular distance from the centre is 1.5 cm., determine the radius of the circle.

  1. 2.5 cm.

  2. 1.5 cm.

  3. 6 cm.

  4. 5 cm.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the chord be AB with length 4 cm. Let O be the center. The perpendicular from O to AB meets AB at M, with OM = 1.5 cm and AM = MB = 2 cm (half of chord length). In right triangle OMA, by Pythagoras theorem: OA² = OM² + AM² = 1.5² + 2² = 2.25 + 4 = 6.25. Therefore, radius OA = √6.25 = 2.5 cm, matching option A. The claimed answer is correct.

Keep practicing — related questions