If the length of the side of a square is $5 \mathrm{cm}$ and the area is $k \mathrm{sq}.\mathrm{cm}.$ find the value of $k$.

If the length of the side of a square is $15 \mathrm{m}$ and the area is $k \mathrm{sq}.\mathrm{m}.$ find the value of $k$.

If the length of the side of a square is $16 \mathrm{cm}$ and the area is $k \mathrm{sq}.\mathrm{cm}.$ find the value of $k$.

If a rectangle has length $=6 \mathrm{cm}$, breadth $=3 \mathrm{cm}$ and the area is $k \mathrm{sq}.\mathrm{cm}.$, find the value of $k$.

If a rectangle has length $=7 \mathrm{m}$, breadth $=4 \mathrm{m}$ and the area is $k \mathrm{sq}.\mathrm{m}.$, find the value of $k$.

If a rectangle has length $=8 \mathrm{cm}$, breadth $=5 \mathrm{cm}$ and the area is $k \mathrm{sq}.\mathrm{cm}.$, find the value of $k$.

If a rectangle has length $=9 \mathrm{m}$, breadth $=6 \mathrm{m}$ and the area is $k \mathrm{sq}.\mathrm{m}.$, find the value of $k$.

If the cost of $1 \mathrm{sq}.\mathrm{m}.$ of a plot is $₹800$, then find the total cost of the plot that is $15 \mathrm{m}$ long and $10 \mathrm{m}$ breadth.

The side of a square is $6 \mathrm{cm}$. The length of a rectangle is $10 \mathrm{cm}$ and its breadth is $4 \mathrm{cm}$. Find the perimeter and area of both the square and rectangle.