What is the perimeter of an equilateral triangle whose area is $4 \sqrt{3} \text{ cm}^2$?

$A$ bed of roses is shaped as shown in the figure below. In the centre is a square and on each side there is a semi-circle. The side of the square is $21 \, m$. If each rose plant needs $6 \, m^{2}$ of space,then the number of plants in the bed is?

The area of a triangle whose sides are $15 \, m$,$16 \, m$,and $17 \, m$ is

$A$ circular ground whose diameter is $35 \ m$ has a $1.4 \ m$ broad garden around it. What is the area of the garden in square metres?

$A$ can go round a circular path $8$ times in $40$ minutes. If the diameter of the circle is increased to $10$ times the original diameter,then the time required by $A$ to go round the new path once,travelling at the same speed as before,is (in $min$)

Perimeter of a square and an equilateral triangle is equal. If the diagonal of the square is $12 \sqrt{2} \text{ cm}$,then find the area of the equilateral triangle.