Four equal-sized circular plates of maximum diameter are cut off from a square paper sheet of area $784 \, cm^2$. The circumference of each plate is ...... $m$.

The sides of a triangle are in the ratio $\frac{1}{4}: \frac{1}{6}: \frac{1}{8}$ and its perimeter is $91\, cm$. The difference of the length of the longest side and that of the shortest side is

The area of the circumcircle of an equilateral triangle is $3 \pi \, cm^2$. The perimeter of the triangle is

What is the area of a triangle whose sides are $9\, cm$,$12\, cm$,and $15\, cm$? (in $cm^2$)

The length of a rectangular field is double its width. Inside the field,there is a square-shaped pond $8 \, m$ long. If the area of the pond is $\frac{1}{8}$ of the area of the field,what is the length of the field? (in $m$)

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