###### Advertisements

###### Advertisements

The moon is about 384000 km from earth and its path around the earth is nearly circular. Find the length of path described by moon in one complete revolution. (Take π = 3.14)

###### Advertisements

#### Solution

Length of path described by moon in one complete revolution = 2πr

= 2 × 3.14 × 384000 ......[∵ Radius = Distance of moon from the earth]

= 2411520 km

#### APPEARS IN

#### RELATED QUESTIONS

The radius of a circle is 7 cm. find the circumference of the circle.

In Fig. there are shown sectors of two concentric circles of radii 7 cm and 3.5 cm. Find the area of the shaded region. Use π = `(\frac { 22 }{ 7 }).`

A pendulum swings through an angle of 30º and describes an arc 8.8 cm in length. Find the length of the pendulum.

From a circular sheet of radius 4 cm, a circle of radius 3 cm is removed. Find the area of the remaining sheet. (Take π = 3.14)

Shazli took a wire of length 44 cm and bent it into the shape of a circle. Find the radius of that circle. Also find its area. If the same wire is bent into the shape of a square, what will be the length of each of its sides? Which figure encloses more area, the circle or the square? (Take `pi = 22/7`)

A sheet of paper is in the form of rectangle ABCD in which AB = 40cm and AD = 28 cm. A semicircular portion with BC as diameter is cut off. Find the area of remaining paper.

Four equal circles, each of radius 5 cm touch each other as shown in fig. Find the area included etween them.

Find the circumferences of a circle whose radius is 7 cm.

^{°},

In the given figure, O is the centre of the sector. \[\angle\]ROQ = \[\angle\]MON = 60^{°} . OR = 7 cm, and OM = 21 cm. Find the lengths of arc RXQ and arc MYN. (\[\pi = \frac{22}{7}\])

In the given figure, if A(P-ABC) = 154 cm^{2 }radius of the circle is 14 cm, find

(1) `∠APC`

(2) l ( arc ABC) .

^{° }find the area of the sector in case.

The radius of a sector of a circle is 7 cm. If the measure of the arc of the sector is 210^{°}, find the area of the sector in case.

The radius of a sector of a circle is 7 cm. If the measure of the arc of the sector is - three right angles; find the area of the sector in case.

The area of a minor sector of a circle is 3.85 cm^{2 }and the measure of its central angle is 36^{°}. Find the radius of the circle.

In the given figure,

\[\square\] PQRS is a rectangle. If PQ = 14 cm, QR = 21 cm, find the areas of the parts x, y, and z.

**Choose the correct alternative answer for the following question.**

The curved surface area of a cylinder is 440 cm 2 and its radius is 5 cm. Find its height.

Choose the correct alternative answer for the following question.

A cone was melted and cast into a cylinder of the same radius as that of the base of the cone. If the height of the cylinder is 5 cm, find the height of the cone.

Choose the correct alternative answer for the following question.

**Choose the correct alternative answer for the following question.**

^{3}.

Diagonal of a square is 20 cm. Find the length and perimeter of the square.

A path of 8 m width runs around the outsider of a circular park whose radius is 17 m. Find the area of the path.

A horse is placed for grazing inside a rectangular field 70 m by 52 m. It is tethered to one corner by a rope 21 m long. On how much area can it graze? How much area is left ungrazed?

The area of a circle inscribed in an equilateral triangle is 154 cm^{2}. Find the perimeter of the triangle.

Radii of the circles are given below, find their areas.

(1) 28 cm

(2) 10.5 cm

(3) 17.5 cm

Areas of some circles are given below find their diameters.

(1) 176 sq cm

(2) 394.24 sq cm

(3) 12474 sq cm

Diameter of the circular garden is 42 m. There is a 3.5 m wide road around the garden. Find the area of the road.

Find the area of the circle if its circumfence is 88 cm.

Find the curved surface area , the total surface area and the volume of a cone if its :

Height = 15 cm , radius = 8 cm

Find the area and perimeter of the circle with the following :

Diameter = 77 cm

Find the curved surface area , the total surface area and the volume of a cone if its :

Height = 16 cm , diameter = 24 cm

The circumference of a garden roller is 280 cm. How many revolutions does it make in moving 490 meters?

The diameter of a cycle wheel is `4 5/11` cm. How many revolution will it make in moving 6.3 km ?

A conical tent requires 264 m^{2} of canvas. If the slant height is 12 m, find the vertical height of the cone.

Find the area and perimeter of the following semi-circle :

Diameter= 5.6 cm

The sum of diameter of two circles is 112 cm and the sum of their areas is 5236 cm^{2} Find the radii of the two circles.

A circus tent is cylindrical to a height of 5 m and conical above it. If its diameter is 42 m and slant height of the cone is 53 m, calculate the total area of the canvas required.

Sand from a cylindrical bucket 32 cm in height and 18 cm in radius is poured onto the ground making a conical heap 24 cm high. Find the radius of the conical heap.

Find the area enclosed between two concentric cirdes of radii 6.3 cm and 8.4 cm. A third concentric circle is drawn outside the 8.4 cm circle, so that the area enclosed between it and 8.4 cm cirde is the same as that between two inner circles. Find the radii of the third circle correct to two decimal places .

Find the circumference of the circle whose area is 81π cm ^{2}.

Find the volume and the surface area of the spheres in the following :

Radius= 2.1 cm

Find the volume and the surface area of the spheres in the following :

Radius = 7 cm

Find the volume and the surface area of the spheres in the following :

Diameter= 6.3 cm

A solid sphere metal is cut through its centre into 2 equal parts. If the diameter of the sphere is 3`1/3` cm , find the total surface of each part, correct to two decimal places.

The diameter of a circle is 28 cm.

Find its :

(i) Circumference

(ii) Area.

The radii of two circles are 25 cm and 18 cm. Find the radius of the circle which has a circumference equal to the sum of circumferences of these two circles.

The radii of two circles are 48 cm and 13 cm. Find the area of the circle which has its circumference equal to the difference of the circumferences of the given two circles.

A wheel has a diameter of 84 cm. Find how many completer revolutions must it make to cover 3.168 km.

Draw the circumcircle of Δ PMT in which PM = 5.4, P = 60°, M = 70°.

The radius of a circle is 21 cm. Find the circumference (Take π = `3 1/7`).

The circumference of a circle is 440 cm. Find its radius and diameter. (Take π = `22/7`)

The diameter of a circular field is 56 m. Find its circumference and cost of fencing it at the rate of ₹80 per m. (Take π =`22/7`)

The radius of two circles are 20 cm and 13 cm. Find the difference between their circumferences. (Take π =`22/7`)

The perimeter of a square and the circumference of a circle are equal. If the length of each side of the square is 22 cm, find:**(i) **perimeter of the square.**(ii)** circumference of the circle.**(iii)** radius of the circle.

The radius of two circles are in the ratio 3 : 5, find the ratio between their circumferences.

The circumferences of two circles are in the ratio 5: 7, find the ratio between their radius.

The circumference of a circle exceeds its diameter by 18 cm. find the radius of the circle.

A circular racing track has inner circumference 528 m and outer circumference 616 m. Find the width of the track.

The inner circumference of a circular track is 264 m and the width of the track is 7 m. Find:**(i)** the radius of the inner track.**(ii)** the radius of the outer circumference.**(iii)** the length of the outer circumference.**(iv) **the cost of fencing the outer circumference at the rate of ₹50 per m.

A bucket is raised from a well by means of a rope which is wound round a wheel of diameter 77 cm. Given that the ascends in 1 minute 28 seconds with a uniform speed of 1.1 m/sec, calculate the number of complete revolutions the wheel makes in raising the bucket. (Take π =22/7)

Complete the table below.

Radius (r) | Diameter (d) | Circumference (c) |

7 cm | ______ |
_______ |

Complete the table below.

Radius (r) | Diameter (d) | Circumference (c) |

_______ | 28 cm | _________ |

Complete the table below.

Radius (r) | Diameter (d) | Circumference (c) |

_______ | _________ | 616 cm |

If the circumference of a circle is 176 cm, find its radius.

The radius of a circular garden is 56 m. What would it cost to put a 4-round fence around this garden at a rate of 40 rupees per metre?

The wheel of a bullock cart has a diameter of 1.4 m. How many rotations will the wheel complete as the cart travels 1.1 km?

The diameter of a circle is 5.6 cm. Find its circumference.

The diameter of the wheel of a cart is 1.05 m. How much distance will the cart cover in 1000 rotations of the wheel?

Find the circumference of a circle whose area is 81πcm^{2}.

The diameter of two circles are 28 cm and 24 cm. Find the circumference of the circle having its area equal to sum of the areas of the two circles.

The wheel of a car makes 10 revolutions per second. If its diameter is 70cm, find the speed of the car in km per hr.

The circumference o a garden roller is 280cm. How many revolutions does it make in moving 490m?

The diameter of a cycle wheel is `4(5)/(11)"cm"`. How many revolutions will it make in moving 6.3km?

A wire when bent in the form of a square encloses an area of 484cm^{2}. If the same wire is bent into the form of a circle, find the area of the circle.

What is the circumference of a circle of diameter 10 cm (Take π = 3.14)?

Find the perimeter of the given shape (Take π = `22/7`).

The radius of a circular plot is 7.7 metres. How much will it cost to fence the plot with 3 rounds of wire at the rate of 50 rupees per metre?

The radius of the wheel of a bus is 0.7 m. How many rotations will a wheel complete while traveling a distance of 22 km?

Diameters of different circles are given below. Find their circumference (Take π = `22/7`)

d = 70 cm

Diameters of different circles are given below. Find their circumference (Take π = `22/7`)

d = 28 mm

Find the circumference of the circles whose radii are given below.

49 cm

The diameter of the bullock cart wheel is 1.4 m. Find the distance covered by it in 150 rotations?

A Rose garden is in the form of circle of radius 63 m. The gardener wants to fence it at the rate of ₹ 150 per metre. Find the cost of fencing?

In the formula, C = 2πr, ‘r’ refers to

If the circumference of a circle is 82π, then the value of ‘r’ is

Circumference of a circle is always ______.

A wheel of a car covers a distance of 3520 cm in 20 rotations. Find the radius of the wheel?

The cost of fencing a circular race course at the rate of ₹ 8 per metre is ₹ 2112. Find the diameter of the race course

In covering a distance s metres, a circular wheel of radius r metres makes `s/(2πr)` revolutions. Is this statement true? Why?

A circular pond is 17.5 m is of diameter. It is surrounded by a 2 m wide path. Find the cost of constructing the path at the rate of Rs 25 per m^{2}.

In reference to a circle the value of π is equal to ______.

Circumference of a circle disc is 88 cm. Its radius is ______.

The area of a semicircle of radius 4r is ______.

Ratio of the circumference of a circle to its diameter is denoted by symbol ______.

Value of π is ______ approximately.

Ratio of circumference of a circle to its radius is always 2π:I.