Question

In rectangle $ABCD$ above, the area of the shaded region is given by $\frac{\pi lw}{4}$. If the area of the shaded region is $7\pi$, what is the total area, to the nearest whole number, of the unshaded regions of rectangle $ABCD$?

• A. $4$
• B. $6$
• C. $8$
• D. $9$
• E. $10$

Answer 1

The correct option is B $6$

Area of shaded region $=\frac{\pi lw}{4}$

or $\frac{\pi lw}{4}=7\pi \Rightarrow lw=28$

Also, area of rectangle $=l\times w=28$

Now, area of unshaded region $=28-7\pi =28-\frac{22}{7}\times 7$

$=6$