Advertisements
Advertisements
Question
Find the circumference of the circles whose radii are given below.
91 mm
Advertisements
Solution
Radius r = 91 mm
Circumference C = 2πr units
= `2 xx 22/7 xx 91`
= 2 × 22 × 13
= 44 × 13
= 572 mm
APPEARS IN
RELATED QUESTIONS
A sector is cut from a circle of radius 21 cm. The angle of the sector is 150º. Find the length of its arc and area.
The minute hand of a circular clock is 15 cm long. How far does the tip of the minute hand move in 1 hour. (Take π = 3.14)
A doorway is decorated as shown in the figure. There are four semi-circles. BC, the diameter of the larger semi-circle is of length 84 cm. Centres of the three equal semicircles lie on BC. ABC is an isosceles triangle with AB = AC. If BO = OC, find the area of the shaded region. (Take `pi = 22/7`)
The outer circumference of a circular race track is 528m. The track is everywhere 14m
wide. Calculate the cost of leveling the track at rate of 50 paise per square metre.
The side of a square is 10 cm. Find the area of the circumscribed circle. [π = 3.14]
Find the circumference of the circle whose area is 81π cm 2.
A cart wheel makes 9 revolutions per second. If the diameter of the wheel is 42 cm, find its speed in km/hr.
A metal wire, when bent in the form of an equilateral triangle of largest area, encloses an area of 484 `sqrt3` cm2. If the same wire is bent into the form of a circle of largest area, find the area of this circle.
The circumference of a circle is eigth time the circumference of the circle with a radius of 12 cm. Find its diameter.
A 4.2m wide road surrounds a circular plot whose circumference is 176m. Find the cost of paving the road at Rs.75per m2.
