Analytic Geometry, Equation of Circle

Question

How can you find the equation of the circle given two tangents and the circle's radius?

Answer 1

You must use the fact that the distance from the unknown center to both tangents is equal to $R$.

($d=\frac{|ux_1 + vy_1 + w|}{\sqrt{u^2 + v^2}}$ where the equation of the line is $ux+vy+w=0$ and the point have the coordinates $(x_1,y_1)$)

After you get the center $I(a,b)$ then the equation of the circle will be $(x-a)^2+(y-b)^2=R^2$