O P Malhotra, S K Gupta and, Anubhuti Gangal Solutions for Chapter: Perimeter and Area, Exercise 6: Exercise

A wheel, $14 \mathrm{cm}$ in diameter, makes $3000$ revolutions per $\mathrm{minute}$. Find its speed in $\mathrm{m}/\sec$.

The moon is about $384000 \mathrm{km}$ from the earth and its path around the earth is nearly circular. Find the circumference of the path (in $\mathrm{km}$) described by the moon in one complete revolution about the earth. $($ use $\pi =3.14)$

There is a circular pond and footpath runs along its boundary. A man walks around it, exactly once, keeping close to the edge. If his step is $55 \mathrm{cm}$ long and he takes exactly $400$ steps to go round the pond, what is the diameter of the pond?

A piece of wire is bent in the shape of a square of each side $6.6 \mathrm{cm}.$ It is rebent to form a circular ring. What is the diameter of the ring (in $\mathrm{cm}$)?

Shaila wants to put a lace on the edge of a circular table cover of diameter $1.4 \mathrm{m}$. Find the length of the lace required and also find its cost, if one metre of lace cost $₹22$.

$\left(\mathrm{\pi }=\frac{22}{7}\right)$ Find the perimeter of the given figure.

The circumferences of two concentric rings are $88 \mathrm{cm}$ and $66 \mathrm{cm}$ respectively. Find the width (in $\mathrm{cm}$) between the rings.

A man runs round a circular field of radius $50 \mathrm{m}$ at a speed of $12 \mathrm{km}/\mathrm{hr}$. How much time is taken by the man to run twenty rounds of the field?