Question 370517
The left side is correct. The right side is where you're going wrong. Note: the diameter is {{{2r}}} and NOT {{{r^2}}}



Since the diameter is {{{d=20sqrt(2)}}}, this means that the radius is half of this at {{{r=d/2=20sqrt(2)/2=10sqrt(2)}}}



So {{{r=10sqrt(2)}}}



Now square 'r' to get {{{r^2=(10sqrt(2))^2=(10sqrt(2))*(10sqrt(2))=(10*10)(sqrt(2)*sqrt(2))=100*2=200}}}



So {{{r^2=200}}}



This means that the equation of the circle is {{{(x-6)^2+(y+3)^2=200}}}



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Jim