Advertisements
Advertisements
प्रश्न
A piece of wire of length 108 cm is bent to form a semicircular arc bounded by its diameter. Find its radius and area enclosed.
Advertisements
उत्तर
Length of wire = 108 cm
Let r be the radius of the semicircle
πr+ 2r = 108
⇒ `r(pi + 2) = 108 ⇒ r(22/7 + 2) = 108`
⇒ `36/7 r = 108 ⇒ r = (108 xx 7)/36 = 21` cm
Area = `(pir^2)/2 = 22/(7 xx 2) xx 21 xx 21 = 1386/2` cm2
= 693 cm2
APPEARS IN
संबंधित प्रश्न
A 36-m-long, 15-m-borad verandah is to be paved with stones, each measuring 6dm by 5 dm. How many stones will be required?
An archery target has three regions formed by three concentric circles as shown in figure. If the diameters of the concentric circles are in the ratios 1 : 2 : 3, then find the ratio of the areas of three regions.
In the following figure, two circles with centres A and B touch each other at the point C. If AC = 8 cm and AB = 3 cm, find the area of the shaded region.
The ratio of the outer and inner perimeters of a circular path is 23 : 22. If the path is 5 metres wide, the diameter of the inner circle is
The length of an arc of the sector of angle θ° of a circle with radius R is
If the perimeter of a semicircular protractor is 72 cm where `pi = 22/7`, then the diameter of protractor is ____________.
The area of a circle is 154 cm2. Its diameter is ____________.
Area of a circle with diameter ‘m’ radius ‘n’ and circumference ‘p’ is ______.
Find the area of the shaded region:
How much distance, in metres, a wheel of 25 cm radius will cover if it rotates 350 times?
