Question

The radius of a circular park is 28m.There is a road of uniform width around the park, which is 7m wide.What is the area of the road?

• A. $1225m^2$
• B. $1386m^2$
• C. $1005m^2$
• D. $1441m^2$

Answer 1

The correct option is B $1386m^2$

As you can see, the road around the park form an outer circle with radius 35 m.
$\therefore$ Area of the road = π( $R^2$ - $r^2$ )
Here, R =35 m and r = 28 m
$\therefore$π( $R^2$ - $r^2$ ) =$\frac{22}{7}$( ${35}^2$ - ${28}^2$ )
= $\frac{22}{7}(1225-784)$
=$\frac{22}{7}\times 441$
=$22\times 63$
=$1386m^2$