Question

The area of the dotted portion in the given figure will be sq. units. (Use $\pi =\frac{22}{7}$)

Answer 1

The area of the shaded region can be found by subtracting the area of the two circles from the area of the outer rectangle.

Let us name the figure as follows:


AB + BC = 14 units
Now, AB = BC = Diameter of circle

$\text{So, AB = BC =}\frac{14}{2}=7\text{units}$

$\text{So, radius of the circle, r =}\frac{7}{2}=3.5\text{units}$

Width of the rectangle is = 2 × r = 2 × 3.5 = 7 cm

So,
Area of the rectangle
$=Length\times Width$
$=14\times 7$
$=98squnits$

Area of the circle
$=\pi \times r^2$

$=\frac{22}{7}\times {3.5}^2$

$=38.5\text{sq. units}$

So, the total area of the two circles
$=2\times 38.5$
$=77squnits$

∴ Area of the shaded region = Area of the rectangle – Total area of the two circles
$=98–77$
$=21squnits$