Advertisements
Advertisements
Question
The diameter of a circle is 42 cm, find its perimeter. If the perimeter of the circle is doubled, what will be the radius of the new circle? (Take π = `22/7`)
Advertisements
Solution
Given, the Diameter of a circle = 42 cm
∴ Radius of circle = `42/2` = 21 cm
The perimeter of the circle = 2πr
=`2xx22/7xx21`
= 132 cm
If the perimeter of the circle doubled
= 2 × 132 =264 cm
Radius = `"C"/(2π)=264/(2xx22/7)`
= `(264xx7)/(2xx22)`
= 42 cm
APPEARS IN
RELATED QUESTIONS
Find the side of the square whose perimeter is 5 m.
The area of a square is 36 cm2. How long are its sides?
Find the perimeter of the following figure:
The area of a rectangular shaped photo is 820 sq.cm. and its width is 20 cm. What is its length? Also find its perimeter
The side of a square is 10 cm. How many times will the new perimeter become if the side of the square is doubled?
Perimeter of a regular octagon of side 6 cm is 36 cm.
The lawn in front of Molly’s house is 12 m × 8 m, whereas the lawn in front of Dolly’s house is 15 m × 5 m. A bamboo fencing is built around both the lawns. How much fencing is required for both?
What is the length of outer boundary of the park shown in the following figure? What will be the total cost of fencing it at the rate of Rs 20 per metre? There is a rectangular flower bed in the center of the park. Find the cost of manuring the flower bed at the rate of Rs 50 per square metre.
A table-top measures 2 m 25 cm by 1 m 50 cm. What is the perimeter of the table-top?
What is the length of the wooden strip required to frame a photograph of length and breadth of 32 cm and 21 cm respectively?
