Find the area of the equilateral triangle having length of each side $50\, cm$.

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 $cm^2$)

The triangular side walls of a flyover have been used for advertisements. The sides of the walls are $122\, m, 22\, m$ and $120\, m$ (see Fig.). The advertisements yield an earning of $Rs. 5000$ per $m^2$ per year. $A$ company hired one of its walls for $3$ months. How much rent did it pay?

$A$ plot,in the shape of a quadrilateral $XYZW$,has $XY = 25 \, m$,$YZ = 60 \, m$,$ZW = 33 \, m$,$WX = 34 \, m$,and $XZ = 65 \, m$. Find its area. (in $, m^2$)

The triangular side walls of a flyover have been used for advertisements. The sides of the walls are $13 \, m$,$14 \, m$,and $15 \, m$. The advertisements yield an earning of $Rs \, 2000$ per $m^2$ a year. $A$ company hired one of its walls for $6$ months. How much rent did it pay? (in $Rs$)

The sides of a triangle measure $20 \, cm$,$24 \, cm$,and $32 \, cm$. Find its semi-perimeter. (in $, cm$)