Advertisements
Advertisements
प्रश्न
The diameters of two circles are 32 cm and 24 cm. Find the radius of the circle having its area equal to the sum of the areas of the two given circles.
Advertisements
उत्तर
Let the area of the resulting circle be r.
π x (16)2 + π x ( 12 )2 = π x r2
256 π + 144 π = π x r2
400π = π x r2
r2 = 400
r = 20 cm
Hence the radius of the resulting circle is 20cm.
APPEARS IN
संबंधित प्रश्न
A rectangular plot measure 125 m by 78 m. It has gravel path 3 m wide all around on the outside. Find the area of the path and the cost of gravelling it at` ₹ 75 per m^2`
Find the area of the quadrilateral ABCD in which in AB=42 cm, BC=21 cm, CD=29cm, DA=34 cm and diagonal BD = 20 cm.
A road which is 7 m wide surrounds a circular park whose circumference is 352 m . Find the area of the road .
Write the area of the sector of a circle whose radius is r and length of the arc is l.
Find the area of sector of circle of radius 21 cm and central angle 1200.
A sector is cut from a circle of radius 21 cm. The angle of the sector is 150°. Find the length of the arc and the area of the sector.
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.
The radii of the inner and outer circumferences of a circular running track are 63 m and 70 m respectively. Find :
(i) the area of the track ;
(ii) the difference between the lengths of the two circumferences of the track.
Find the area of a circle of radius 30 cm (use π = 3.14).
The area of the circle whose diameter is 21 cm is ____________.
