In the figure, $\mathrm{A},\mathrm{B}$ and $\mathrm{C}$ are three squares with side lengths $a,b,c$ respectively.If $\mathrm{A}=81{\mathrm{m}}^2, \mathrm{B}=49 {\mathrm{m}}^2$, then the area of $\mathrm{C}$ is.

 

An athletic track $21 \mathrm{m}$ wide consists of two straight sections each $150 \mathrm{m}$long joined by semicircular ends whose diameter is $70 \mathrm{m}$.Calculate the area of the track.

Students of a school took out a rally as part of the cleanliness campaign. They walked through the lanes in a group. The group walked through $AB,BC,CD$ and $DA.$ They then cleared the area enclosed within the lanes. If $Ab=12 m, BC=40 m, CD=12 m \text{and} DA=28 m,$ how much area did they clean. In what other ways can an awareness towards cleanliness be generated among people $?$ 

Suppose you have been asked to make an aeroplane from the coloured paper, as shown in figure. Find the total area of paper that you would need.

A square and a rectangular field with measurements as given in the figure have the same perimeter. Which field has a larger area$?$