Corresponding angle Postulate
If 2 parallel lines are cut by a transversal, then the corresponding angles are congruent
Alternate interior angle theorem
If 2 parallel lines are cut by a transversal, then the alternate interior angles are congruent
Same side interior angle theorem
If 2 parallel lines are cut by a transversal, then the same side interior angles are supplementary
Alternate exterior angle theorem
If 2 parallel lines are cut by a transversal, then the alternate exterior angles are congruent
Same side exterior angle theorem
If 2 parallel lines are cut by a transversal, then the same side exterior angles are supplementary
Perpendicular transversal theorem
If a transversal is perpendicular to 1 of 2 parallel lines then it is perpendicular to the other
Converse of the Corresponding angle Postulate
If 2 lines are cut by a transversal and the corresponding angles are congruent, the then lines are parallel
Converse of the Alternate interior angle theorem
If 2 line are cut by a transversal and the alternate interior angles are congruent, then the lines are parallel
Converse of the same side interior angle theorem
If 2 line are cut by a transversal and the same side interior angles are supplementary, then the lines are parallel
Converse of the alternate exterior angle theorem
If 2 line are cut by a transversal and the alternate exterior angles are congruent, then the lines are parallel
Converse of the same side exterior angle theorem
If 2 line are cut by a transversal and the same side exterior angles are supplementary, then the lines are parallel
Converse of the perpendicular transversal theorem
In a plane, 2 lines perpendicular to the same line, are parallel
Parallel postulate
Given a line and a point not on that line, there is exactly 1 line THROUGH THE POINT parallel to the given line
Perpendicular postulate
Given a line and a point not on that line, there is exactly 1 line THROUGH THE POINT perpendicular to the given line
Theorem 3-10 (parallel transitive)
2 lines parallel to the same line, are parallel to each other
Triangle exterior angle theorem
The measure of an exterior angle in a triangle is equal to the sum of the remote INTERIOR angles
Interior angle sum theorem
The sum of the measures of the interior angles of a CONVEX polygon is (n - 2)*180
Exterior angle sum theorem
The sum of the measures of the exterior angles of a polygon is 360 degrees
Triangle ANGLE SUM theorem
The sum of the measures of the angles of a triangle equals 180 degrees
Describe corollaries
A statement that follows readily after a theorem
3rd angle corollary (tri. <. + theo)
If 2 angles of 1 triangle are congruent to 2 angles of another triangle, then the 3rd angles are congruent
Corollary 2 (tri. <. + theo.)
Each angle of angle equiangular triangle has a measure of 60 degrees
Corollary 3 (tri. <. + theo.)
In a triangle, there can be AT MOST 1 right or 1 obtuse angle
Corollary 4 (tri. <. + theo.)
The acute angles of a right triangle are complementary