Find the Circumference of the Circle Whose Area is 25 Times the Area of the Circle with Radius 7 Cm. - Mathematics

Advertisements
Advertisements
Sum

Find the circumference of the circle whose area is 25 times the area of the circle with radius 7 cm. 

Advertisements

Solution

Area of the circle with radius 7 cm = π r2 

`= 22/7 xx 7 xx 7`

= 154 cm2

Area of new circle = 25 x area of the drde with radius 7 cm 

= 25 x 154 cm2 

= 3850 cm2

Therefore ,

π R2 = 3850

R2 = `3850 xx 7/22`

R = 1225

R = 35 cm

Radius of new circle = 35 cm 

Circumference of new circle = 2 π R

`= 2 xx 22/7 xx 35`

= 220 cm

Hence, Circumference of new circle = 220 cm  

  Is there an error in this question or solution?
Chapter 19: Mensuration I - Exercise 19.1

APPEARS IN

Frank ICSE Class 10 Mathematics Part 2
Chapter 19 Mensuration I
Exercise 19.1 | Q 10

Video TutorialsVIEW ALL [2]

RELATED QUESTIONS

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


In figure, ΔABC is an isosceles triangle with perimeter 44 cm. The base BC is of length 12 cm. Side AB and side AC are congruent. A circle touches the three sides as shown in the figure below. Find the length of the tangent segment from A to the circle.


The wheels of a car are of diameter 80 cm each. How many complete revolutions does each wheel make in 10 minutes when the car is traveling at a speed of 66 km per hour? [Use Π = 22/7]


Three semicircles each of diameter 3 cm, a circle of diameter 4.5 cm and a semicircle of radius 4.5 cm are drawn in the given figure. Find the area of the shaded region


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)


The minute hand of a circular clock is 15 cm long. How far does the tip of the minute hand move in 1 hour. (Take π = 3.14)


The circumference of a circle exceeds diameter by 16.8 cm. Find the circumference of
circle.


A horse is tied to a pole with 28m long string. Find the area where the horse can graze.


A square water tank has its side equal to 40m, there are 4 semicircular flower beds grassy plots all around it. Find the cost of turfing the plot at Rs 1.25/sq.m


In the given figure, the radius of the circle is 7 cm and m ( arc MBN) = 60°,
find  A(O - MCN). 

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. (\[\pi = \frac{22}{7}\]) 


The radius of a sector of a circle is 7 cm. If the measure of the arc of the sector is - 30°  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.


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 ratio of circumference and area of a circle is 2:7. Find its circumference.

Choose the correct alternative answer for the following question.
If measure of an arc of a circle is 160° and its length is 44 cm, find the circumference of the circle.
 

Choose the correct alternative answer for the following question.

 Find the curved surface area of a cone of radius 7 cm and height 24 cm.

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.

 Find the volume of a cube of side 0.01 cm.

Choose the correct alternative answer for the following question.

Find the side of a cube of volume 1 m3.

The difference between the circumference and radius of a circle is 37cm. Using `pi = 22/7` , find the circumference of the circle. 


The sum of the radii of two circles is 7 cm, and the difference of their circumferences is 8 cm. Find the circumference of the circles.


If the sum of the circumferences of two circles with radii R1 and R2 is equal to the circumference of a circle of radius R, then ______.


The circumference of a circle is 22 cm. Find its area.


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 area and perimeter of the circle with the following :

Radius= 2.8 cm 


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

Diameter= 35 cm 


A bucket is raised from a well by means of a rope wound round a wheel of diameter 35 cm. If the bucket ascends in 2 minutes with a uniform speed of 1.1 m per sec, calculate the number of complete revolutions the wheel makes in raising the bucket.


The area of a circular ring enclosed between two concentric circles is 88 cm 2. Find the radii of the two circles, if their difference is 1 cm.


A conical tent requires 264 m2 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 :

Radius= 1.4 cm


A 4.2 m wide road surrounds a circular plot whose circumference is 176 m. Find the cost of paving the road at Rs 75 m 2


The sum of diameter of two circles is 112 cm and the sum of their areas is 5236 cm2 Find the radii of the two circles. 


A horse is tied with a 21 m laig rope to the corner of a field which is in the shape of an equilateral triangle. Find the area of the field over which it can graze.


Find the circumference of the circle whose area is 81π cm 2


A cart wheel makes 9 revolutions per second. If the diameter of the wheel is 42 cm, find its speed in km/hr. 


The base circumferences of two cones are the same. If their slant heights are in the ratio 5 : 4, find the ratio of their curved surface areas. 


The diameter of a right circular cylinder is 12 m and the slant height is 10 m. Find its curved surface area and the total surface area . 


Find the total surface area and volume of a hemisphere whose radius is 10 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. 


Find the diameter of the sphere for the following : 

Surface Area = 221. 76 cm2 


Find the diameter of the sphere for the following : 

Surface Area = `576pi`cm2


The circumference of a circular field is 308 m. Find is:
(i) Radius
(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 radius of a circle is 5 m. Find the circumference of the circle whose area is 49 times the area of the given circle.


An express train is running between two stations with a uniform speed. If the diameter of each wheel of the train is 42 cm and each wheel makes 1200 revolutions per minute, find the speed of the train.


There are two circular gardens A and B. The circumference of garden A is 1.760 km and the area of garden B is 25 times the area of garden A. Find the circumference of garden B.


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`)


Find the radius of the circle whose circumference is equal to the sum of the circumferences of the circles having radius 15 cm and 8 cm.


Find the diameter of a circle whose circumference is equal to the sum of circumference of circles with radius 10 cm, 12 cm, and 18 cm.


The circumference of a circle is eigth time the circumference of the circle with a radius of 12 cm. Find its diameter.


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


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.


In the adjoining figure, the radius is 3.5 cm. Find:
(i) The area of the quarter of the circle correct to one decimal place.
(ii) The perimeter of the quarter of the circle correct to one decimal place. ( Take π = `22/7`)


Complete the table below.

Radius (r)  Diameter (d) Circumference (c)
_______ 28 cm _________

Complete the table below.

Radius (r)  Diameter (d) Circumference (c)
_______ _________ 616 cm

Complete the table below.

Radius (r)  Diameter (d) Circumference (c)
_______ _________ 72.6 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 area and perimeter of the circles with following: Diameter = 35cm


The sum of the circumference and diameter of a circle is 176 cm. Find the area of the circle.


A cart wheel makes 9 revolutions per second. If the diameter of the wheel is 42cm, find its speed in km per hour. (Answer correct to the nearest km)


A wire when bent in the form of a square encloses an area of 484cm2. If the same wire is bent into the form of a circle, find the area of the circle.


Find the circumference of the circle whose area is 25times the area of the circle with radius 7cm.


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.

91 mm


The diameter of a circular well is 4.2 m. What is its circumference?


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


A ground is in the form of a circle whose diameter is 350 m. An athlete makes 4 revolutions. Find the distance covered by the athlete


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 decorating the circumference of a circular lawn of a house at the rate of ₹ 55 per metre is ₹ 16940. What is the radius of the lawn?


Length of tape required to cover the edges of a semicircular disc of radius 10 cm is ______.


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


Value of π is ______ approximately.


Circumference ‘C’ of a circle can be found by multiplying diameter ‘d’ with ______.


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


ABCD is a given rectangle with length as 80 cm and breadth as 60 cm. P, Q, R, S are the midpoints of sides AB, BC, CD, DA respectively. A circular rangoli of radius 10 cm is drawn at the centre as shown in the given figure. Find the area of shaded portion.


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)


Share
Notifications



      Forgot password?
Use app×