SOLUTION: A pleasant day to you Sir / Madam,
please do help me with this direct square variation question, I am not sure of my answer.
The area of a circle varies directly as the squ
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-> SOLUTION: A pleasant day to you Sir / Madam,
please do help me with this direct square variation question, I am not sure of my answer.
The area of a circle varies directly as the squ
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Question 684629: A pleasant day to you Sir / Madam,
please do help me with this direct square variation question, I am not sure of my answer.
The area of a circle varies directly as the square of its radius. If the area is 78.5 when the radius is 5. Find the area when the radius is 8.
Thank you very much! Answer by Jolliano(16) (Show Source):
You can put this solution on YOUR website! A = kr^2
where A = area
k = constant of variation/proportionality
r = radius.
When A = 78.5,r=5
Since
A = kr^2
78.5 =k *5^2 = 25k
k = 78.5/25 = 3.1
So,when r = 8,
A = 3.1 * 8^2
=3.1 * 64
=198.4cm^2
