Advertisements
Advertisements
प्रश्न
Find the area and perimeter of the following semicircles: Radius = 1.4cm
Advertisements
उत्तर
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 Area of a Semi-circle with radius 1.4cm
= `pi(1.4)^2/(2)`
= `(22)/(7) xx (1.4)^2/(2)`
= 3.08cm2
The Perimeter of a Semi-circle with radius r
= π(1.4) + 2 x 1.4
= 1.4(π + 2)
= `14(22/7 + 2)`
= `(36)/(7) xx 1.4`
= 7.2cm.
APPEARS IN
संबंधित प्रश्न
The short and long hands of a clock are 4 cm and 6 cm long respectively. Find the sum of distances travelled by their tips in 2 days. (Take π = 22/7)
An arc of length 15 cm subtends an angle of 45° at the centre of a circle. Find in terms of 𝜋, radius of the circle.
A road which is 7m wide surrounds a circular park whose circumference is 352m. Find the area of road.
The parallel sides of trapezium are 12 cm and 9cm and the distance between them is 8 cm. Find the area of the trapezium.
Find the circumferences of a circle whose radius is 7 cm.
A boy is cycling in such a way that the wheels of his bicycle are making 140 revolutions per minute. If the diameter of a wheel is 60 cm, calculate the speed (in km/h) at which the boy is cycling.
The diameter of a wheel is 1.4m. How many revolutions does it make in moving a distance of 2.2 kms?
If the circumference of a circle is 82π, then the value of ‘r’ is
Is it true that the distance travelled by a circular wheel of diameter d cm in one revolution is 2 π d cm? Why?
ABCD is a given rectangle with length as 80 cm and breadth as 60 cm. P, Q, R, S are the midpoints of sides AB, BC, CD, DA respectively. A circular rangoli of radius 10 cm is drawn at the centre as shown in the following figure. Find the area of shaded portion.
