Advertisements
Advertisements
प्रश्न
The circumference of a circle is 31.4 cm. Find the radius and the area of the circle? (Take π = 3.14)
Advertisements
उत्तर
Let r be the radius of circle.
Circumference = 2πr = 31.4 cm
2 × 3.14 × r = 31.4
r = 5 cm
Area = 3.14 × 5 × 5
= 78.50 cm2
APPEARS IN
संबंधित प्रश्न
The cost of painting the four walls of a room 12 m long at `₹ 30 per m^2 is ₹ 7560 per m^2` and the cost of covering the floor with the mat at ₹` 25 per m^2 is ₹ 2700 `. find the dimensions of the room.
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`
In the following figure, from a rectangular region ABCD with AB = 20 cm, a right triangle AED with AE = 9 cm and DE = 12 cm, is cut off. On the other end, taking BC as diameter, a semicircle is added on outside' the region. Find the area of the shaded region. [Use π =]`22/7` [CBSE 2014]
From each of the two opposite corners of a square of side 8 cm, a quadrant of a circle of radius 1.4 cm is cut. Another circle of radius 4.2 cm is also cut from the centre as shown in the following figure. Find the area of the remaining (Shaded) portion of the square. (Use π = 22/7)
A child makes a poster on a chart paper drawing a square ABCD of side 14 cm. She draws four circles with centre A, B, C and D in which she suggests different ways to save energy. The circles are drawn in such a way that each circle touches externally two of the three remaining circles (in the following figure). In the shaded region she write a message 'Save Energy'. Find the perimeter and area of the shaded region.
(Use π = 22/7)
If the circumference of two circles are in the ratio 2 : 3, what is the ratio of their areas?
If the perimeter of a semi-circular protractor is 36 cm, then its diameter is
On decreasing the radius of a circle by 30%, its area is decreased by
Find the radius and area of a circle, whose circumference is :
(i) 132 cm
(ii) 22 m
The circumference of a circular park is 352 m. Find the area of the park
