What is the area of a triangle whose sides are $9\, cm$,$12\, cm$,and $15\, cm$? (in $cm^2$)

The area of a trapezium is $2500 \, m^2$. One of its parallel sides is $75 \, m$. If the distance between the two parallel sides is $40 \, m$,then find the length of the other parallel side in $m$.

One of the diagonals of a rhombus is double the other diagonal. Its area is $25\, cm^{2}$. The sum of the diagonals is.......$cm$

If the side of a square is increased by $50 \%$,the percent increase in its area is: (in $\%$)

The ratio of length and breadth of a rectangular plot is $8:5$ respectively. If the breadth is $60\, m$ less than the length,what is the perimeter of the rectangular plot? (in $m$)

$A$ lawn is in the shape of a rectangle of length $60 \ m$ and width $40 \ m$. Inside the lawn,there is a footpath of uniform width $1 \ m$ bordering the lawn. The area of the path is ....... $m^2$.