Advertisements
Advertisements
प्रश्न
A steel wire, when bent in the form of a square, encloses an area of 121 cm2. The same wire is bent in the form of a circle. Find area the circle.
Advertisements
उत्तर
Area of a square = ( Side )2
⇒ 121 = ( Side )2
⇒ Side of a square = 11 cm
Now,
The perimeter of a square = Perimeter of a circle
⇒ 4 x Side = Perimeter of a circle
⇒ 4 x 11 = Perimeter of a circle
⇒ Perimeter of a circle = 44 cm
⇒ 2πr = 44 ....( r is radius of a circle )
⇒ r = `44/[2π] = 44/[ 2 xx 22/7]` = 7 cm
∴ Area of a circle = πr2 = `22/7 xx 7 xx 7 = 154 "cm"^2`
APPEARS IN
संबंधित प्रश्न
Find the length of the diagonal of a square whose area is `128 cm^2` Also, find its perimeter.
The cost of fencing a square lawn at ₹ 14 per meter is ₹ 28000. Find the cost of mowing the lawn at ₹ 54 100 per `m^2`
A chord PQ of length 12 cm subtends an angle of 120° at the centre of a circle. Find the area of the minor segment cut off by the chord PQ.
What is the length (in terms of π) of the arc that subtends an angle of 36° at the centre of a circle of radius 5 cm?
The area of the largest triangle that can be inscribed in a semi-circle of radius r is
The area of a sector whose perimeter is four times its radius r units, is
Find the lengths of the arcs cut off from a circle of radius 12 cm by a chord 12 cm long. Also, find the area of the minor segment.
A 7m wide road surrounds a circular garden whose area is 5544m2. Find the area of the road and the cost of tarring it at the rate of Rs.150 per m2.
Thenmozhi wants to level her circular flower garden whose diameter is 49 m at the rate of ₹ 150 per m2 Find the cost of levelling
Find the diameter of a circle whose area is equal to the sum of the areas of the two circles of radii 24 cm and 7 cm.
