Theorem 2-1 to 2-8
Theorem 2-6/T2-6
If the exterior sides of two adjacent acute angles are perpendicular, then the angles are complementary
Theorem 2-8/T2-8
If two angles are complements of congruent angles (or the same angle), then the two angles are congruent
Theorem 2-7/T2-7
If two angles are supplements of congruent angles (or the same angle), then the two angles are congruent
Theorem 2-4/T2-4
If two lines are perpendicular, then they form congruent adjacent angles
Theorem 2-5/T2-5
If two lines form congruent adjacent angles, then the lines are perpendicular
Theorem 2-1/T2-1
Midpoint Theorem: if M is the midpoint of AB, then AM=1/2AB and MB=1/2AB
Theorem 2-2/T2-2
Angle Bisector Theorem: If BX is the bisector of <ABC, then m<ABX=1/2m<ABC and m<XBC=1/2m<ABC
Theorem 2-3/T2-3
Vertical angles are congruent