On decreasing each side of an equilateral triangle by $2\, cm$,there is a decrease of $4\sqrt{3}\, cm^2$ in its area. The length of each side of the triangle is.........$cm$.

If the perimeter of a rectangular field is $200\, m$ and its breadth is $40\, m$,then its area is (in $m^2$):

$A$ lawn is in the shape of a rectangle of length $60 \ m$ and width $40 \ m$. Inside the lawn,there is a footpath of uniform width $1 \ m$ bordering the lawn. The area of the path is ....... $m^2$.

An open box is made of wood $2\, cm$ thick. Its internal length is $86\, cm,$ breadth $46\, cm$ and height is $38\, cm.$ The cost of painting the outer surface of the box at $Rs.$ $10$ per $m^2$ is? (in $Rs.$)

If the length of one diagonal of a rhombus is $80 \%$ of the length of the other diagonal,the area of the rhombus is how many times the square of the length of the longer diagonal?

The length of a rectangular plot is $60\%$ more than its breadth. If the difference between the length and the breadth of that rectangle is $24\, cm$,what is the area of that rectangle? (in $cm^2$)