# Finding tangent points of circle inside a triangle

Hi,

This is really a part 2 of a previous questions of finding intersecting points of a circle and triangle. I'd like to run my approach by you all to see if I'm thinking correctly. Maybe there's a faster way but here's how I see it.

Given the attached screen shot(sorry for crude image), with the help of Henry, I can find the side (s) which will ultimately allow me to find the tangent points of p1, p2.

Using formulas for missing side/angles of a triangle which I found online yesterday, I can find angles a,c which will in turn give me angles b,d. From this I can calculate (s) as being:

d = 10
s = d/2 * (1/tan(angle/2))


Now that I have all the necessary angles and side (s), I can use my existing formulas to find the missing sides which will be my x, y of tangent points p1, p2.

This seems to be alot of manual work so please let me know if any of you see an easier way. Henry, thanks much for the helping me find 's'.

David

-
Link to previous question: math.stackexchange.com/questions/266220/… –  user53153 Jan 4 '13 at 19:02