Circumference of a Circle

The ratio of the circumferences of two circles is $3:4$.Find the ratio of their areas.

The distance around a circular region is called its _____.

A piece of wire is in the form of a rectangle whose length and breadth are $40 \mathrm{cm}$ and $26 \mathrm{cm}$ respectively. It is rebent in the form of a circle. Find the radius of the circle.

A piece of wire is bent in the shape of a square of side $11 \mathrm{cm}$. It is rebent to form a circular ring. What is the diameter of the ring?

[Hint: Circumference of the circle $=$ Perimeter of the square]

A piece of wire in the form of a rectangle of $8.9 \mathrm{cm}$ long and $54 \mathrm{mm}$ broad is reshaped and bent in the form of a circle. Find the radius of the circle in $\mathrm{mm}$.

There are two concentric circles as shown in the following figure. The circumference of outer circle is $132 \mathrm{cm}$ and circumference of the inner circle is $88 \mathrm{cm}$. Find the differences between their radii i.e., $\left(\mathrm{R}-\mathrm{r}\right)$

The ratio of circumferences of two circles is $5:3$. What is the ratio of their radii?

Find the perimeter of the figure.

Find the perimeter of the figure.

Find the perimeter of the figure.

Find the perimeter of the figure.

Find the perimeter of the figure.

Find the radius of a circle whose circumference is $30.8 \mathrm{m}$.

Find the radius of a circle whose circumference is $66 \mathrm{m}$.

Find the radius of a circle whose circumference is $22 \mathrm{cm}$.

Find the radius of a circle whose circumference is $44 \mathrm{m}$.

Find the circumference of a circle whose diameter is $7 \mathrm{cm}$.

Find the circumference of a circle whose diameter is $10 \mathrm{cm}$.

Find the circumference of a circle whose diameter is $28 \mathrm{cm}$.

Find the circumference of a circle whose diameter is $14 \mathrm{cm}$.