Question

There are two circular gardens A and B. The circumference of garden A is $1.760km$ and the area of garden B is $25$ times the area of garden A. Find the circumference of garden B.

• A. $8.8km.$
• B. $8.8m$
• C. $8.8k{m}^2$
• D. $88km$

Answer 1

Answer: (A)

$8.8km.$

Let radius of garden A be $r$ and that of garden B be $R$.

Circumference of the circle is $2\pi r$

For garden A, $2\pi r=1.76$

$\pi R^2=25\times \pi r^2$ ...Given

$⟹R=5r$

Circumference of garden B$=2\pi R=2\pi \left(5r\right)=5\times 2\pi r=5\times 1.76=8.8km$