Advertisements
Advertisements
Question
Find the area of the shaded region:
Advertisements
Solution
Let radius of smaller circle be r and bigger circle be R
From the figure, r = `7/2` cm and R = `7/2 + 7 = 21/2`cm
∴ Area of shaded region = Area of bigger circle – Area of smaller circle
= πR2 – πr2
= π(R2 – r2)
= `π(21/2 xx 21/2 - 7/2 xx 7/2)`
= `π(441/4 - 49/4)`
= `22/7 xx 392/4`
= 308 cm2
Hence, the area of shaded region is 308 cm2.
APPEARS IN
RELATED QUESTIONS
A circular flower garden has an area of 314 m2. A sprinkler at the centre of the garden can cover an area that has a radius of 12 m. Will the sprinkler water the entire garden? (Take π = 3.14)
A footpath of uniform width runs all around the inside of a rectangular field 54 m long and 35 m wide. If the area of the path is 420 m2, find the width of the path.
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]
If diameter of a circle is increased by 40%, then its area increase by
If three circles of radius a each, are drawn such that each touches the other two, prove that the area included between them is equal to `4/25 a^2`. [Take `sqrt(3) = 1.73` and π = 3.14.]
In the given figure, PQ = 24 cm, PR = 7 cm and O is the centre of the circle. Find the area of the shaded region. [Take π = 3.14.]
The area of a sector of a circle with radius r, making an angle of x° at the centre is ______.
Area of circle of radius ‘n’ units is
The area of a circle is 154 cm2. Its diameter is ____________.
Is the area of the circle inscribed in a square of side a cm, πa2 cm2? Give reasons for your answer.
