In a right-angled triangle,the length of the hypotenuse is $29\,cm$ and one of the sides forming the right angle is $21\,cm$. Then,the semi-perimeter of the triangle is ............ $cm$.

In a trapezium $ABCD$, $AB \parallel CD$. If $AB = 30 \, cm$, $BC = 17 \, cm$, $CD = 20 \, cm$, and $DA = 9 \, cm$, then find its area. (in $cm^2$)

For a plank in the shape of a parallelogram,the adjacent sides measure $12 \, cm$ and $17 \, cm$,and one of its diagonals measures $25 \, cm$. Find the cost of painting the plank at the rate of Rs. $3$ per $cm^2$.

State whether the following statement is True or False and justify your answer:
The area of $\Delta ABC$ is $8 \, cm^2$ in which $AB = AC = 4 \, cm$ and $\angle A = 90^{\circ}$.

The area of an isosceles triangle having base $2 \, cm$ and the length of one of the equal sides $4 \, cm$ is

Find the area of the trapezium $PQRS$ given in the figure.