area and circumference

May 2010
2
0
Hi all,
i am not able to get the relation between area and circumference in the given below.could any one please help me out


If the circumference of a circle is decreased by 50% then the percentage of decrease in its area is?


Regards
Padma
 
Apr 2009
96
0
Circumference = 2*pi*r which can be rewritten as r= C/(2*pi)
Area = pi*(r^2)
substitute with 50% of C
pi * ((1/2)(1/(2*pi))^2

What is your coefficient ?
 

Prove It

MHF Helper
Aug 2008
12,883
4,999
Hi all,
i am not able to get the relation between area and circumference in the given below.could any one please help me out


If the circumference of a circle is decreased by 50% then the percentage of decrease in its area is?


Regards
Padma
If you magnify the length of a shape by a scale factor \(\displaystyle k\), then the area is magnified by \(\displaystyle k^2\).

In this case, the length scale factor \(\displaystyle k = \frac{1}{2}\).

So what is the area scale factor?
 
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