I have three known points defining a triangle: $A(x_a,y_a), B(x_b,y_b)$ and $C(x_c,y_c)$.
How do I round the angle (ABC) of a specific radius $r$?
I know that the slope of $AB$ edge is: $(y_a - y_b) / ( x_a - x_b)$.
My circle with center (unknown) $O:(x_o, y_o)$ will have an equation $(y_a - y_o)^2 + (x_a -x_o) = r^2$.
The point $B$ will also satisfy the equation of the circle.
Knowing the slopes of the line equations of my triangle and that my circle has a radius of known $r$, I have troubles to find the center of my circle and the points $M,N$ where my circle will intersect with the edges of the triangle. The points $M,N$ are also the tangential points of the circle.
After working little the math it seems that I have too many unknowns for my system.
I would really appreciate any help.