Advertisements
Advertisements
प्रश्न
The radii of two circles are in the ratio 3: 8. If the difference between their areas is 2695π cm2, find the area of the smaller circle.
Advertisements
उत्तर
Let the radius of the two circles be 3r and 8r respectively.
area of the circle having radius 3r = π(3r)2
= 9πr2
area of the circle having radius 8r = π(8r)2
= 64πr2
According to the question
64πr2 - 9πr2 = 2695π
55r2 = 2695
r2 = 49
r = 7 cm
Hence the radius of the smaller circle is 3 x 7 = 21 cm
Area of the smaller circle is given by
A = πr2 =`22/7 xx 21^2 = 1386 "cm"^2`
APPEARS IN
संबंधित प्रश्न
The perimeter of a rectangular plot of land is 80 m and its breadth is 16 m. Find the length and area of the plot.
Find the area of minor segment of a circle of radius 14 cm, when the angle of the corresponding sector is 600 .
If the perimeter of a sector of a circle of radius 6.5 cm is 29 cm, then its area is
The minute hand of a clock is 15 cm long. Calculate the area swept by it in 20 minutes.
In the given figure, PQ = 24, PR = 7 cm and O is the centre of the circle. Find the area of the shaded region.
In the given figure, a square OABC has been inscribed in the quadrant OPBQ. If OA = 20 cm, then the area of the shaded region is
The given figures show a rectangle ABCD inscribed in a circle as shown alongside.
If AB = 28 cm and BC = 21 cm, find the area of the shaded portion of the given figure.
Two circles touch each other externally. The sum of their areas is 58πcm2 and the distance between their centres us 10cm. Find the radii of the two circles.
Lalitha wants to buy a round carpet of radius is 63 cm for her hall. Find the area that will be covered by the carpet
The area (in cm2) of the circle that can be inscribed in a square of side 8 cm is ____________.
