If the diameter of each circle is $14 \, cm$ and $DC = CE$,find the area of $\Delta BDE$ in $cm^2$.

If the length of a rectangle is increased by $10 \%$ and its breadth is decreased by $10 \%,$ then its area

The area of a square is $196 \, cm^2$. Its side is half the radius of a circle. The circumference of the circle is equal to the breadth of a rectangle. If the perimeter of the rectangle is $712 \, cm$,what is the length of the rectangle? (in $cm$)

The perimeter of a rhombus is $60 \, cm$ and one of its diagonals is $24 \, cm$. The area (in $sq. cm$) of the rhombus is

Height of an equilateral triangle is $6 \, cm$. Find its side? (in $cm$)

Three sides of a triangular field are $20\, m$,$21\, m$,and $29\, m$ long,respectively. The area of the field is.......$m^2$.