Advertisements
Advertisements
प्रश्न
Find the area and perimeter of the following semicircles: Diameter = 7cm
उत्तर
The radius of a Circle with diameter d is r = `"d"/(2)`
The Area of a Semi-circle with radius r = `(pi"r"^2)/(2)`
The Perimeter of a Semi-circle with radius r
= πr + 2r
= r(π + 2)
= `"r"(22/7 + 2)`
= `(36)/(7) xx "r"`
The radius of a Circle with diameter 7 is r
= `(7)/(2)`
= 3.5cm
The Area of a Semi-circle with radius 3.5
= `(pi(3.5)^2)/(2)`
= 19.25cm2
The Perimeter of a Semi-circle with radius r
= π x 3.5 + 2 x 3.5
= 3.5(π + 2)
= `3.5(22/7 + 2)`
= `(36)/(7) xx 3.5`
= 25cm.
APPEARS IN
संबंधित प्रश्न
If the perimeter of a semi-circular protractor is 66 cm, find the diameter of the protractor (Take π = 22/7).
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.
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`)
A horse is placed for grazing inside a rectangular field 40m by 36m and is tethered to one corner by a rope 14m long. Over how much area can it graze.
The side of a square is 10 cm. find the area of circumscribed and inscribed circles.
A wire when bent in the form of an equilateral triangle encloses an area of `121sqrt(3) "cm"^2`. The same wire is bent to form a circle. Find the area enclosed by the circle.
Find the area and perimeter of the circle with the following :
Diameter = 77 cm
Find the area and perimeter of the following sector :
Radius= 6 cm, angle at the centre is 70°
Find the area of a circular field that has a circumference of 396m.
A circular pond is surrounded by a 2 m wide circular path. If outer circumference of circular path is 44 m, find the inner circumference of the circular path. Also find area of the path.
