# Area of a Circle

## Trending Questions

**Q.**

An athlete completes one round of a circular track of diameter $200\mathrm{m}$ in $40\mathrm{s}.$ What will be the distance covered and the displacement at the end of $2\mathrm{min}20\mathrm{s}?$

**Q.**

How is land distributed between the farmers of Palampur?

**Q.**

Recall, $\mathrm{\pi}$ is defined as the ratio of the circumference (say $\mathrm{c}$) of a circle to its diameter, (say $\mathrm{d}$) . That is, $\mathrm{\pi}=\frac{\mathrm{c}}{\mathrm{d}}$. This seems to contradict the fact that $\mathrm{\pi}$ is irrational. How will you resolve this contradiction?

**Q.**If the perimeter of a square and the circumference of a circle are equal, then the area of the square is ________ the area of the circle.

- greater than
- twice
- half
- less than

**Q.**

The circumference of the circle is $132cm$; find its area.

**Q.**Question 7

Shanti Sweets Stall was placing an order for making cardboard boxes for packing their sweets. Two sizes of boxes were required. The bigger of dimensions 25 cm×20 cm×5 cm and the smaller of dimension 15 cm×12 cm×5 cm. For all the overlaps, 5% of the total surface area is required extra. If the cost of the cardboard is Rs. 4 for 1000cm2, find the cost of cardboard required for supplying 250 boxes of each kind.

**Q.**

How do you prove that the circumference of a circle is $2\mathrm{\pi}r$?

**Q.**

The radius of a circle is stated as $2.12cm.$ Its area should be written as

**Q.**What is radius of curvature of projectile motion?

**Q.**

Find the area of the circle whose diameter is 10m. Express your answer in cm2. [2 MARKS]

**Q.**Two cross road each of width 10m cut at right angles through the centre of a rectangular park of length 700m and breadth 300m and parallel to its sides .find the area of the roads.also find the area of the park excluding the crossroads in hectares.

**Q.**

Question 13

A circular flower bed is surrounded by a path 4 m wide. The diameter of the flower bed is 66 m. What is the area of this path? (Take π=3.14)

**Q.**

Find the area of the following circle given that$:$ radius$=30cm$

**Q.**

Length and breadth of a piece of rectangular wire are 18 cm and 15 cm. It is bent into the shape of a circle . find the diametre of the circle

**Q.**

The volumes of two spheres are in the ratio $64:27$. Find the difference of their surface area if the sum of their radii is $7cm$.

**Q.**

The length of the equator of the globe is $44\mathrm{cm}$. Find its surface area.

**Q.**

Radius of the outer circle is 18 cm and the radius of the inner circle is 7 cm. What is the area of the region between the outer and the inner circles?

361π cm

^{2}192.5 cm

^{2}133 cm

^{2}275π cm

^{2}

**Q.**

The minute hand of a circular clock is 14 cm. How far does the tip of the minute hand move in 1 hour?

**Q.**

Prove that angle bisector of any angle of a triangle and perpendicular bisector of the opposite side if intersect, they will intersect on the circumcircle of the triangle.

**Q.**

A hemispherical tank is made up of an iron sheet 1 cm thick. If the inner radius is 1 m, then find the volume of the iron used to make the tank.

[Assume π=227]

**Q.**

How many times a circular wheel of diameter 56 CM must rotate to go 704 m?

**Q.**Find the area of the circle with radius 7 m. Take π=227.

- 154 m2
- 308 m2
- 310 m2

**Q.**

The side of given square is equal to twice the radius of the circle. Which of them will have greater area?

[3 MARKS]

**Q.**

Find the area of a triangle whose sides are 48cm, 14cm and 50 cm.

305 cm2

336 cm2

265 cm2

330 cm2

**Q.**

A farmer has a rectangular field of length and breadth $250m$and $160m$ respectively.He wants to fence it with $4$rounds of barbed wire .What is the total length of barbed wire to be used in fencing ?

**Q.**Area of a semicircle is 308 cm2, then find its diameter.

- 14 cm
- 21 cm
- 28 cm
- 49 cm

**Q.**

If the diameter of a circle is $20\mathrm{cm}$, what is the area?

**Q.**

Radius of a circle is doubled. What will be the ratio between the area of the new circle and the area of the original circle?

5:3

2:3

4:8

4:1

**Q.**

A car has two wipers which do not overlap. Each wiper has a blade of length $25$ cm sweeping through an angle of $115\xb0$. Find the total area cleaned at each sweep of the blades.

**Q.**

Observe the shapes 1, 2, 3 and 4 in the figure. Which of the following statements is not correct?

Shapes 1 and 4 have the same area as well as the same perimeter.

Shapes 1, 2 and 4 have the same area.

Shapes 1, 3 and 4 have different areas and different perimeters.

Shapes 1, 3 and 4 have the same perimeter.