Advertisements
Advertisements
Question
The sum of the circumference and diameter of a circle is 176 cm. Find the area of the circle.
Advertisements
Solution
Let the radius of a circle = r cm
Circumference of a circle = 2πr cm
Diameter of a circle = 2r cm
Now,
Circumference of a circle + Diameter of a circle = 176cm
⇒ 2πr + 2r = 176
⇒ 2πr(π + 1) = 176
⇒ 2r(3.14 + 1) = 176
⇒ 2r x 4.14 = 176
⇒ r = `(176)/(2 xx 4.14)`
= 21.26cm
∴ Area of a circle
= πr2
=3.14 x 21.26 x 21.26
= 1419.24cm2.
APPEARS IN
RELATED QUESTIONS
A pendulum swings through an angle of 30º and describes an arc 8.8 cm in length. Find the length of the pendulum.
An elastic belt is placed round the rim of a pulley of radius 5 cm. One point on the belt is pulled directly away from the centre O of the pulley until it is at P, 10 cm from O. Find the length
of the belt that is in contact with the rim of the pulley. Also, find the shaded area.
The radius of a sector of a circle is 7 cm. If the measure of the arc of the sector is - three right angles; find the area of the sector in case.
Choose the correct alternative answer for the following question.
The curved surface area of a cylinder is 440 cm 2 and its radius is 5 cm. Find its height.
The areas of two circles are in the ratio 4: 9. What is the ratio between their circumferences?
Find the area and perimeter of the circle with the following:
Diameter= 35 cm
Find the curved surface area , the total surface area and the volume of a cone if its :
Height = 8 cm , diameter = 12 cm
A cylindrical bucket, whose base radius is 20 cm, is filled with water to a height of 25 cm. A heavy iron spherical ball of radius 10 cm is dropped to submerge completely in water in the bucket. Find the increase in the level of water.
The circumference of a circle exceeds its diameter by 450 cm. Find the area of the circle.
Diameters of different circles are given below. Find their circumference (Take π = `22/7`)
d = 28 mm
