Multiple choice

If the radius of a circle is increasing by $10$% then the area of new corresponding is

  1. $1.21\pi r^{2}$
  2. $1.21\pi r$
  3. $1.24\pi r^{2}$
  4. $12.1\pi r^{2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If the radius r increases by 10%, the new radius is 1.1r. The new area is pi * (1.1r)^2 = pi * 1.21 * r^2 = 1.21 * pi * r^2.

AI explanation

The area of a circle is pi times radius squared. If the radius increases by 10 percent, the new radius becomes 1.1r, and squaring this gives 1.21 times r squared. The new area is therefore 1.21 times pi times r squared.

Keep practicing — related questions