Postulate or

Theorem

STATEMENTS
1. If two distinct planes intersect, then their intersection is
a line.

2. The sum of the measures of the angles at a point is 360°.

3. Complements of congruent angles are congruent.

4. Every plane contains at least three noncollinear points.

5. The measure of the exterior angle of a triangle is equal
to the sum of the measures of its two remote interior
angles.​