If the circumference and the area of a circle are numerically equal,then the diameter is equal to

$A$ 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?

$A$ triangle and a parallelogram are constructed on the same base such that their areas are equal. If the altitude of the parallelogram is $100 \, m$,then the altitude of the triangle is

If the circumference of a circle is equal to the perimeter of a square,what is the ratio of the area of the circle to the area of the square?

The length of a rectangle is twice the diameter of a circle. The circumference of the circle is equal to the area of a square of side $22\, cm$. What is the breadth of the rectangle if its perimeter is $668\, cm$? (in $cm$)

$ABCD$ is a parallelogram as shown in the figure. Find its area in $cm^2$.