Advertisements
Advertisements
Question
The circumference of a circle is eigth time the circumference of the circle with a radius of 12 cm. Find its diameter.
Solution
Let the radius of the bigger circle = R, and Let the radius of the smaller circle = r.
r = 12 cm
According to the problem,
2πR = 8 × 2πr
2πR = 8 × 2π × 12
R = `(8 xx 2pi xx 12)/(2pi)`
R = 8 × 12
R = 96
Diameter = 2 × 96
= 192 cm
APPEARS IN
RELATED QUESTIONS
A sector is cut from a circle of radius 21 cm. The angle of the sector is 150º. Find the length of its arc and area.
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
Choose the correct alternative answer for the following question.
Two circular pieces of equal radii and maximum area, touching each other are cut out from a rectangular cardboard of dimensions 14 cm ⨯ 7 cm. Find the area of the remaining cardboard.
The diameters of the front and rear wheels of a tractor are 80 cm and 2 m respectively. Find the number of revolutions that a rear wheel makes to cover the distance which the front wheel covers is 800 revolutions.
The area of a square is the same as the area of a square. Their perimeters are in the ratio
Find the area and perimeter of the circle with the following :
Diameter = 77 cm
Find the area and perimeter of the following semi-circle :
Diameter= 7 cm
A metal wire, when bent in the form of an equilateral triangle of largest area, encloses an area of 484 `sqrt3` cm2. If the same wire is bent into the form of a circle of largest area, find the area of this circle.
The diameter of a cycle wheel is `4(5)/(11)"cm"`. How many revolutions will it make in moving 6.3km?
