The sides of a triangular plot are in the ratio of $3 : 5 : 7$ and its perimeter is $300\, m$. Find its area.

$A$ floral design on a floor is made up of $16$ tiles which are triangular,the sides of the triangle being $9\, cm, 28\, cm$ and $35\, cm$ (see Fig.). Find the cost of polishing the tiles at the rate of $50p$ per $cm^2$.

$A$ field is in the shape of a trapezium whose parallel sides are $25\, m$ and $10\, m$. The non-parallel sides are $14\, m$ and $13\, m$. Find the area of the field. (in $, m^{2}$)

$A$ kite in the shape of a square with a diagonal $32\, cm$ and an isosceles triangle of base $8\, cm$ and sides $6\, cm$ each is to be made of three different shades as shown in the figure. How much paper of each shade has been used in it?

There is a slide in a park. One of its side walls has been painted in some colour with a message "$KEEP$ $THE$ $PARK$ $GREEN$ $AND$ $CLEAN$". If the sides of the wall are $15 \, m$,$11 \, m$ and $6 \, m$,find the area painted in colour.

An isosceles triangle has a perimeter of $30 \, cm$ and each of the equal sides is $12 \, cm$. Find the area of the triangle.