Advertisements
Advertisements
प्रश्न
Find the radius of a circle whose perimeter and area are numerically equal.
उत्तर
Let the radius of the required circle be r.
Now, Area of circle = Perimeter of the circle
⇒ πr2 = 2π × r
⇒ r2 = 2r
⇒ r2 - 2r =0
⇒ r(r - 2) = 0
⇒ r - 2 = 0 [∴ r ≠ 0]
⇒ r = 2 units
Hence, the radius of the circle is 2 units.
APPEARS IN
संबंधित प्रश्न
In Fig. 4, ABCD is a square of side 14 cm. Semi-circles are drawn with each side of square as diameter. Find the area of the shaded region.
(use `pi=22/7`)
The perimeter of a rhombus is 60 cm. If one of its diagonal us 18 cm long, find
(i) the length of the other diagonal, and
(ii) the area of the rhombus.
The shape of the cross section of a canal is a trapezium. If the canal is 10 m wide at the top, 6 m wide at the bottom and the area of its cross section is `640m^2` , find the depth of the canal.
Find the area of a quadrant of a circle whose circumference is 88 cm.
Four equal circles are described about the four corners of a square so that each touches two of the others, as shown in the figure. Find the area of the shaded region, if each side of the square measures 14 cm.
Sum of the areas of two squares is 157 m2. If the sum of their perimeters is 68 m, find the sides of the two squares.
Find the diameter of a circle whose circumference is equal to the sum of circumference of circles with radius 10 cm, 12 cm, and 18 cm.
A bucket is raised from a well by means of a rope which is wound round a wheel of diameter 77 cm. Given that the ascends in 1 minute 28 seconds with a uniform speed of 1.1 m/sec, calculate the number of complete revolutions the wheel makes in raising the bucket. (Take π =22/7)
A bucket is raised from a well by means of a rope wound round a wheel of diameter 35 cm. If the bucket ascends in 2 minutes with a uniform speed of 1.1 m per sec, calculate the number of complete revolutions the wheel makes in raising the bucket.
A Rose garden is in the form of circle of radius 63 m. The gardener wants to fence it at the rate of ₹ 150 per metre. Find the cost of fencing?
