This topic is 3028 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

Recommended Posts

hello, im not so good at math, please help me, i need help calculating the 2-dimensional coordinate positions of the common tangent lines (l1 & l2 in image) of cirles C1 and C2, i.e the T1, T2 , T3 & T4 point coordinates like in this image: knowing following: the center of the circles C1 & C2 , also radii R & r and the distance "d" between centers of circles. thank you !

Share on other sites
This sounds like a homework question.

Are you allowed to use vector math? If you create certain vectors, then for some of them you'll have an equation for their length (which is given), and for others you can rely on the fact that the dot product of two perpendicular vectors is 0.

Share on other sites
http://www.geometrictools.com/LibFoundation/Miscellaneous/Miscellaneous.html

look at TangentsToCircles.

Share on other sites
i can use vector math.

thank you for replies,
i think i solved it.

Share on other sites
Quote:
 Original post by Gage64This sounds like a homework question.Are you allowed to use vector math? If you create certain vectors, then for some of them you'll have an equation for their length (which is given), and for others you can rely on the fact that the dot product of two perpendicular vectors is 0.

Gage64, based on redbaseone's prior, and recent, posts, I believe this is not homework. I believe he is working on a pathfinding/pathfollowing implementation for a game.

1. 1
2. 2
Rutin
22
3. 3
JoeJ
18
4. 4
5. 5

• 17
• 40
• 23
• 13
• 13
• Forum Statistics

• Total Topics
631726
• Total Posts
3001910
×