The radius of an outer circle is 21cm and the inner circle is 14cm. Find the area of an cricular ring.
Answers
Answered by
34
Radius of outer circle = 21 cm
Area of outer circle = π r²
= 22/7 × 21 × 21
= 22 × 3 × 21
= 1386 cm²
Radius of innet circle = 14 cm
Area of inner circle = π r²
= 22/7 × 14 × 14
= 22 × 2 × 14
= 616
Area of outer ring = Area of outer circle - Area of inner circle
= 1386 cm² - 616 cm²
= 770 cm²
Hence, required area = 770 cm²
Answered by
28
Given :-
The radius of an outer circle is 21cm and the inner circle is 14cm.
To Find :-
Area of circular ring
Solution :-
Area of ring = π(R² - r²)
Area = 22/7(21² - 14²)
Area = 22/7(441 - 196)
Area = 22/7 × 245
Area = 22 × 35
Area = 770 cm²
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