Question

If the radius of a circle is doubled, its area becomes ____________.

Options

• 2 times

• 4 times

• 8 times

• 16 times

Answer 1

If the radius of a circle is doubled, its area becomes 4 times.

Explanation:

original area = `pi "r"^2`

when the radius is doubled

New area = `pi (2  "x")^2`

`= 4 xx pi  "x"^2`

area will increase 4 times.