Question

in the figure sides of a square are surrounded by four same semicircles each of radius 10.5cm the perimeter of the region so formed is

Answer 1

Now, we take out the Circumference of the semicircle which is given by
$\frac{1}{2} \times 2\pi \: r \\ = \pi \: r \\ 3.14 \times 10.5 = 4.71$
Now, there are four Semicircles Hence, we multiply it by 4.
$4.71 \times 4 = 18.84$