position of the point inside the triangle i don't understand how to find it?

Dear Piyai,

One method would be plug the x and z values into the plane equation for the triangle and solve for y, i.e. (off the top of my head, so no guarantee of correctness):

ax + by + cz + d = 0
ax + cz + d = -by
y = -(ax + cz + d) / b

You can easily compute the plane equation for the triangle from its vertices (A, B, and C). 

Cracking IIT just got more exciting,It s not just all about getting assistance from IITians, alongside Target Achievement and Rewards play an important role. ASKIITIANS has it all for you, wherein you get assistance only from IITians for your preparation and win by answering queries in the discussion forums. Reward points 5 + 15 for all those who upload their pic and download the ASKIITIANS Toolbar, just a simple  to download the toolbar….

So start the brain storming…. become a leader with Elite Expert League ASKIITIANS

Thanks

Aman Bansal

Askiitian Expert