The ratio of the equal sides to the base of an isosceles triangle is $3:1$ If the perimeter of the triangle is $28 \mathrm{cm}$, then find its area.

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

The perimeter of a triangle is $50 \mathrm{cm}$. One side of a triangle is $4 \mathrm{cm}$ longer than the smaller side and the third side is $6 \mathrm{cm}$ less than twice the smaller side. Find the area of the triangle.