A square is inscribed in a circle. If the area of the shaded region is 224 cm², calculate the area of the square.

Find the area of triangle with following sides. [All measures are in cm.]

$10,17,21$

Find the area of triangle with following sides. [All measures are in cm.]

$17,25,28$

Find the area of triangle with following sides. [All measures are in cm.]

$25,39,40$

In figure, $OA=7 cm, AB=3.5 cm$. Calculate the perimeter and area of the shaded region.

The figure shows a running track around a grassed enclosure which consists of rectangle $\mathrm{PQRS}$ with a surrounding semicircular region at each end. $\mathrm{PQ}=200 \mathrm{m}, \mathrm{PS}=70 \mathrm{m}$. The outer perimeter of the track if the width of the track is $7 \mathrm{m}$.

The gate at the entrance of a garden looks like the given figure from the front. The length and breadth of each rectangle are $4 \mathrm{m}$ and $70 \mathrm{cm}$ respectively. The width of the entrance is $2.8 \mathrm{m}$. The top arch is made up of two concentric semicircles. Find the height of the entrance