Advertisements
Advertisements
Question
Find the area and perimeter of the circles with following: Diameter = 77cm
Advertisements
Solution
The radius of a Circle with diameter d is r = `"d"/(2)`
The Area of a Circle with radius r = πr2
The radius of a Circle with diameter 77 is r
= `(77)/(2)`
= 38.5cm
The Area of a Circle with radius r
= π(38.5)2
= `(22)/(7) xx (38.5)^2`
= 4658.5cm2
The Circumference of a Circle with diameter d is πd
The Circumference of a Circle with diameter 77 is π x 77
= `(22)/(7) xx 77`
= 242cm.
APPEARS IN
RELATED QUESTIONS
The minute hand of a clock is 10cm long. Find the area of the face of the clock described by the minute hand between 9 A.M. and 9.35 A.M.
The radii of two circles are 8 cm and 6 cm respectively. Find the radius of the circle having area equal to the sum of the areas of the two circles.
Shazli took a wire of length 44 cm and bent it into the shape of a circle. Find the radius of that circle. Also find its area. If the same wire is bent into the shape of a square, what will be the length of each of its sides? Which figure encloses more area, the circle or the square? (Take `pi = 22/7`)
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)
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.
The side of a square is 10 cm. Find the area of the inscribed circle [π = 3.14]
The area of a circle inscribed in an equilateral triangle is 154 cm2. Find the perimeter of the triangle.
PQRS is a diameter of a circle of radius 6 cm. The lengths PQ, QR and RS are equal. Semicircles are drawn with PQ and QS as diameters, as shown in the given figure. If PS = 12 cm, find the perimeter and area of the shaded region.
Find the dimensions of a rectangular park whose perimeter is 60 m and area 200 m2.
Is it true that the distance travelled by a circular wheel of diameter d cm in one revolution is 2 π d cm? Why?
