# Thread: finding the equation of the circle

1. ## finding the equation of the circle

find the equation of the circle that passes through the (2,2) and tangent to the line x =1 and x = 6?

What would be the best way to answer this question? can you please give me an illustration?

thank you in advance and God bless you..

"WE SHOULD PRAY FOR JAPAN"

2. The equation of a circle is $\displaystyle (x-h)^2+(y-k)^2= r^2$ you have the point (2,2) to sub in and given it is tangent to x=1 and x=6 then the radius is half the difference of these two numbers.

3. An obvious point- since x= 1 and x= 6 are parallel, the center of the circle lies on the vertical line half way between them. That immediately gives you both the x-coordinate of the center and the radius. Then use pickslides equation, with x= y=2, to find the y-coordinate of the center.