Question

the sum of radii of two circular is 7 cm and difference of a circumference is 8 cm find the radius of circle

Answer 1

Let the radi of the two circles be r1 and r2

Given r1+r2=7 {1} )
$\times 2\pi$
= 2π r1 +2π r2 = 14π

Also given 2π r1 - 2π r2=8 {2}

Now add both the equations.

4π r1 = 14π +8
Now find the value of r1 and put in eq 1 to get the value of r2.

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