Question

The diameter of a circular garden is 70 metres On its outside, there is a road 7 meter wideThen the area of the road is

• A. $1540m^2$
• B. $1584m^2$
• C. $1694m^2$
• D. $1562m^2$

Answer 1

Answer: (C)

$1694m^2$

Radius of the garden $=35m$

Radius of the garden with road $=35+7=42m$

Area of the region between two concentric circles with radius of outer circle R, and inner circle r $=\pi (R^2-r^2)$

Hence, the area of the road $=\pi ({42}^2-{35}^2)=\frac{22}{7}\times (42+35)\times (42-35)=\frac{22}{7}\times 77\times 7=1694m^2$