The lengths of three medians of a triangle are $9 \, cm$,$12 \, cm$,and $15 \, cm$. The area (in $cm^2$) of the triangle is

Four circular cardboard pieces,each of radius $7\, cm$,are placed in such a way that each piece touches two other pieces. The area of the space enclosed by the four pieces is.......$cm^2$.

In $\triangle ABC,$ a line parallel to side $BC$ intersects sides $AB$ and $AC$ at points $D$ and $E$ respectively. Point $D$ divides $AB$ in the ratio $1:4.$ If the area of $\triangle ABC$ is $200 \text{ cm}^2,$ what is the area (in $\text{cm}^2$) of quadrilateral $DECB$?

Three sides of a triangular field are $20\, m$,$21\, m$,and $29\, m$ long,respectively. The area of the field is.......$m^2$.

In the given figure,$PB$ is one-third of $AB$ and $BQ$ is one-third of $BC.$ If the area of $BPDQ$ is $20 \, cm^{2},$ then what is the area (in $cm^{2}$) of $ABCD$?

What is the area of a given right-angled triangle?
$I.$ The length of the hypotenuse is $5\, cm$.
$II.$ The perimeter of the triangle is four times that of its base.
$III.$ One of the angles of the triangle is $60^{\circ}$.