The perimeter of a rhombus is $100\,cm$ and one of its diagonals measures $48\,cm$. Then,the length of the other diagonal is ....... $cm.$

$A$ field is in the shape of a trapezium having parallel sides $90 \, m$ and $30 \, m$. These sides meet the third side at right angles. The length of the fourth side is $100 \, m$. If it costs $\operatorname{Rs} 4$ to plough $1 \, m^2$ of the field,find the total cost of ploughing the field (in $\operatorname{Rs}$).

The perimeter of an isosceles triangle is $32 \, cm$. The ratio of the equal side to its base is $3: 2$. Find the area of the triangle.

Find the area of a triangular field,two sides of which are $510\,m$ and $520\,m$ and the perimeter is $1560\,m$. Also,find the cost of the field at the rate of Rs. $21$ per $m^2$.

Write True or False and justify your answer.
If the side of a rhombus is $10 \, cm$ and one diagonal is $16 \, cm$,the area of the rhombus is $96 \, cm^2$.

The sides of a triangular plot are in the ratio of $4: 7: 9$ and its perimeter is $500 \, m$. Find its area.