Theorem 2: A line and a point not on the line are contained in exactly one plane.
1. Line l and point P not on l. 1. Given
2. l contains at least 2 points, A and B. 2. Postulate 1
3. P, A, and B are noncollinear. 3. Definition of noncollinear.
4. P, A, and B are in exactly one plane, m. 4. Postulate 2.
5. l is in m. 5. Postulate 3.