Advertisements
Advertisements
Question
A wire of length 1320 cm is made into circular frames of radius 7 cm each. How many frames can be made?
Advertisements
Solution
Length of the wire = 1320 cm
Radius of each circular frame = 7 cm
Circumference of the frame 2πr units = `2 xx 22/7 xx 7 "cm"`
= 2 × 22
= 44 cm
∴ Number of frames made = `"length of the wire"/"circumference of one frame"`
= `1320/44`
= 30
30 frames can be made.
APPEARS IN
RELATED QUESTIONS
In Fig. 4, O is the centre of a circle such that diameter AB = 13 cm and AC = 12 cm. BC is joined. Find the area of the shaded region. (Take π = 3.14)

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 circumference of a circle exceeds diameter by 16.8 cm. Find the circumference of
circle.
Find the area of a right – angled triangle, the radius of whose, circumference measures 8 cm and the altitude drawn to the hypotenuse measures 6 cm.
Find the circumferences of a circle whose radius is 7 cm.
The wheel of a motor cycle is of radius 35 cm. How many revolutions per minute must the wheel make so as to keep a speed of 66 km/hr ?
In the given figure, find the area of the shaded region, if ABCD is a square of side 14 cm and APD and BPC are semicircles.

The inside perimeter of a running track shown in the figure is 400 m. The length of each of the straight portions is 90 m, and the ends are semicircles. If the track is 14 m wide everywhere, find the area of the track. Also, find the length of the outer boundary of the track.

Find the circumference of the circles whose radii are given below.
49 cm
The numerical value of the area of a circle is greater than the numerical value of its circumference. Is this statement true? Why?
