Advertisements
Advertisements
Question
The area of the circular ring enclosed between two concentric circles is 88 cm2. Find the radii of the two circles, if their difference is 1 cm.
Advertisements
Solution
Let the radius of outer circle = R cm
And, the radius of inner circle = r cm
Then, we have
R - r = 1 ....(i)
And, π(R2 - r2) = 88
⇒ (R - r)(R + r)
= `88 xx (7)/(22)`
⇒ 1 x (R + r) = 28
⇒ R + r = 28 ....(ii)
Adding (i) and (ii), we get
2R = 29
⇒ R = 14.5cm
Now, R + r = 28
⇒ 14.5 + r = 28
⇒ r = 13.5cm.
APPEARS IN
RELATED QUESTIONS
A circular flower bed is surrounded by a path 4 m wide. The diameter of the flower bed is 66 m. What is the area of this path? (π = 3.14)
Two concentric circles of radii a and b (a > b) are given. Find the length of the chord of the larger circle which touches the smaller circle.
In the the following figure, PSR, RTQ and PAQ are three semicircles of diameter 10 cm, 3 cm and 7 cm respectively. Find the perimeter of shaded region.
If the circumference of two circles are in the ratio 2 : 3, what is the ratio of their areas?
The area of a circle is 98.56 cm2. Find its circumference.
A round table cover has six equal designs as shown in the given figure. If the radius of the cover is 35 cm, then find the total area of the design.
The given figures show a rectangle ABCD inscribed in a circle as shown alongside.
If AB = 28 cm and BC = 21 cm, find the area of the shaded portion of the given figure.
The sum of diameters of two circles is 112cm and the sum of their areas is 5236cm2. Find the radii of the two circles.
Area of circle of radius ‘n’ units is
Is the area of the largest circle that can be drawn inside a rectangle of length a cm and breadth b cm (a > b) is πb2 cm2? Why?
