Question 363723
Areas of two circles. The radius of a circle is 1 meter longer than the radius
 of another circle.
 If their areas differ by 5 square meters, then what is the radius of each?
:
Two radii, r, (r+1)
{{{pi*(r+1)^2}}} - {{{pi*r^2}}} = 5
{{{pi*(r^2+2r+1)}}} - {{{pi*r^2}}} = 5
Divide both sides by pi
{{{(r^2+2r+1)}}} - {{{r^2}}} = {{{5/pi}}}
2r + 1 = 1.59
2r = 1.59 - 1
2r = .59
r = {{{.59/2}}}
r = .295 m is the radius of the smaller, 1.295 m is the radius of the larger
:
:
Check this on a calc: enter (pi*1.295^2) - (pi*.295^2) = 4.995 ~ 5