If the perimeter and the area of a circle are numerically equal, what is the radius of the circle?

Answer and explanation

Correct answer: A.

  1. Step 1: Express perimeter (circumference) and area using radius : Perimeter , and Area .
  2. Step 2: Set them numerically equal: . Dividing both sides by (since radius ) yields .
Answer
.
Why not the others: '' incorrectly equates to the constant ; '' squares the correct radius; '' confuses radius with circumference approximation.

Practise more Geometry and Trigonometry.

Free questions with an explanation for every one, and full timed CBSE Class 10 mock tests.