Advertisements
Advertisements
प्रश्न
If the radius of a circle is tripled, the area becomes ______.
विकल्प
9 times
3 times
6 times
30 times
Advertisements
उत्तर
If the radius of a circle is tripled, the area becomes 9 times.
Explanation:
Let r be the radius of a circle.
∴ Area of circle = πr2
If radius is tripled, then new radius will be 3r.
∴ Area of new circle = π(3r)2 = 9π2 = 9 times of original
Hence, the area of a circle becomes 9 times to the original area.
APPEARS IN
संबंधित प्रश्न
The length and the breadth of a rectangular garden are in the ratio 9 : 5. A path 3.5 m wide, running all around inside it has an area of 1911 m2. Find the dimensions of the garden.
ABCDEF is a regular hexagon with centre O (in the following figure). If the area of triangle OAB is 9 cm2, find the area of : (i) the hexagon and (ii) the circle in which the haxagon is incribed.
If π is taken as `22/7` the distance (in metres) covered by a wheel of diameter 35 cm, in one revolution, is
A square is inscribed in a circle. Find the ratio of the areas of the circle and the square.
The cost of fencing a circular field at the rate of Rs 25 per metre is Rs 5500. The field is to be ploughed at the rate of 50 paise per m2. Find the cost of ploughing the field. [Take `π = 22/7`].
From a thin metallic piece in the shape of a trapezium ABCD in which AB || CD and ∠BCD = 90°, a quarter circle BFEC is removed. Given, AB = BC = 3.5 cm and DE = 2 cm, calculate the area of remaining (shaded) part of metal sheet.
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.
Two circles touch externally. The sum of their areas is 130π sq. cm and the distance between their centers is 14 cm. Find the radii of the circles.
The floor of the circular swimming pool whose radius is 7 m has to be cemented at the rate of ₹ 18 per m2. Find the total cost of cementing the floor
Find the area of the shaded region:
