Advertisements
Advertisements
प्रश्न
Find the circumference of a circle whose area is 81πcm2.
Advertisements
उत्तर
The Area of a Circle with radius r = πr2
Here, Area of a Circle = 81πcm2
⇒ 81π = πr2
⇒ 81 = r2
⇒ r = 9cm
The Circumference of a Circle with radius r = 2πr
The Circumference of a Circle with radius 9
= 2π x 9
= 18πcm.
APPEARS IN
संबंधित प्रश्न
A sheet of paper is in the form of rectangle ABCD in which AB = 40cm and AD = 28 cm. A semicircular portion with BC as diameter is cut off. Find the area of remaining paper.
In the given figure, if A(P-ABC) = 154 cm2 radius of the circle is 14 cm, find
(1) `∠APC`
(2) l ( arc ABC) .
The radii of two circles are 19 cm and 9 cm, Find the radius of the circle which has circumference equal to the sum of the circumferences of the two circles.
A bucket is raised from a well by means of a rope wound round a wheel of diameter 35 cm. If the bucket ascends in 2 minutes with a uniform speed of 1.1 m per sec, calculate the number of complete revolutions the wheel makes in raising the bucket.
Find the diameter of a circle whose circumference is equal to the sum of circumference of circles with radius 10 cm, 12 cm, and 18 cm.
A bucket is raised from a well by means of a rope which is wound round a wheel of diameter 77 cm. Given that the ascends in 1 minute 28 seconds with a uniform speed of 1.1 m/sec, calculate the number of complete revolutions the wheel makes in raising the bucket. (Take π =22/7)
The numerical value of the area of a circle is greater than the numerical value of its circumference. Is this statement true? Why?
Circumferences of two circles are equal. Is it necessary that their areas be equal? Why?
Circumference of a circle disc is 88 cm. Its radius is ______.
