How to find area of cirlcle's shaded (Ring) part Need Formula and examples...
Answers
Answer:
Here we will discuss about the area of a circular ring along with some example problems.
The area of a circular ring bounded by two concentric circle of radii R and r (R > r)
= area of the bigger circle – area of the smaller circle
= πR2 - πr2
= π(R2 - r2)
= π(R + r) (R - r)
Therefore, the area of a circular ring = π(R + r) (R - r), where R and r are the radii of the outer circle and the inner circle respectively.
Solved example problems on finding the area of a circular ring:
1. The outer diameter and the inner diameter of a circular path are 728 m and 700 m respectively. Find the breadth and the area of the circular path. (Use π =
22
7
).
Solution:
The outer radius of a circular path R =
728m
2
= 364 m.
The inner radius of a circular path r =
700m
2
= 350 m.
Area of a Circular Ring
Therefore, breadth of the circular path = R - r = 364 m - 350 m = 14 m.
Area of the circular path = π(R + r)(R - r)
=
22
7
(364 + 350) (364 - 350) m2
=
22
7
× 714 × 14 m2
= 22 × 714 × 2 m2
= 31,416 m2
Therefore, the area of the circular path = 31416 m