# Triangle intersection in 3D

### Problem

Triangle A, B, C is defined by three points:
\begin{aligned} A &= (5, 2, 5) \\ B &= (-3, 3, 5) \\ C &= (4, -4, 4) \\ \end{aligned}
A ray intersects the plane defined by A, B, C at a point, I.
If I, equals, left parenthesis, 7, point, 4, comma, minus, 3, point, 2, comma, 4, point, 2, right parenthesis, is I inside triangle, A, B, C?