Advertisements
Advertisements
प्रश्न
If radius of a circle is increased to twice its original length, how much will the area of the circle increase?
पर्याय
1.4 times
2 times
3 times
4 times
Advertisements
उत्तर
4 times
Explanation:
Let r be the radius of the circle.
∴ Area of circle = π2
If radius is increased to twice its original length, then radius will be 2r.
Now, area of new circle = π(2r)2 = 4π2 = 4 times of original area
Hence, the area of circle will be increased by 4 times.
APPEARS IN
संबंधित प्रश्न
In the following figure, two circles with centres A and B touch each other at the point C. If AC = 8 cm and AB = 3 cm, find the area of the shaded region.
In the following figure, shows the cross-section of railway tunnel. The radius OA of the circular part is 2 m. If ∠AOB = 90°, calculate:
the height of the tunnel
In the following figure, ABCD is a trapezium of area 24.5 cm2 , If AD || BC, ∠DAB = 90°, AD = 10 cm, BC = 4 cm and ABE is quadrant of a circle, then find the area of the shaded region. [CBSE 2014]
What is the diameter of a circle whose area is equal to the sum of the areas of two circles of diameters 10 cm and 24 cm?
The perimeter of a certain sector of a circle of radius 6.5 cm in 31 cm. Find the area of the sector.
Four equal circles, each of radius 5 cm, touch each other, as shown in the figure. Find the area included between them.
In the following figure, a rectangle ABCD enclosed three circles. If BC = 14 cm, find the area of the shaded portion (Take π = 22/7)
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.
A lawn is in the shape of a semicircle of diameter 42m. the lawn is surrounded by a flower bed of width 7m all round. Find the area of the flower bed in m2.
Find the area enclosed between two concentric circles of radii 6.3cm and 8.4cm. A third concentric circle is drawn outside the 8.4cm circle. So that the area enclosed between it and the 8.4cm circle is the same as that between the two inner circles. Find the radii of the third circle correct to two decimal places.
