Geometry set 1
Biconditional
an angle is a right angle, if and only if it has a measure of 90°
Contrapositive
if AB + BC does not = AC , then B is not between A and AC.
conditional statement
if B is between A and C, then AB + BC = AC.
inverse
if B is not between A and C, the AB + BC does not = AC.
Midpoint thereom
if M is the midpoint of AB, then AM=1/2 AB, MB=1/2 AB
Law of Detachment
if p→q is a true conditional statement and p is true, then q is true.
Law of syllogism
if p→q, then p→r .
Distance Formula
√(x₂-x₁)²+(y₂-y₁)²
Mid-point Formula
(x₁+x₂)÷2, (y₁+y₂)÷2
Vertical Angles
Opposite ∠'s are ≅
Definition of Angle Bisector
Ray that splits an ∠ into 2 ≅ ∠'s
Definition of Supplementary angles
180°
Definition of Linear Pair
2 ∠'s who's sides are opposite rays + sum = 180°
Definition of complementary angles
90°
converse
If AB + BC = AC, then B is between A and C.
Segment Addition Postulate
If B is between A and C, then AB+BC=AC
Definition of Midpoint
If B is the midpoint of AC then AB and AC are ≅ (an ∠ or segment broken into 2 equal parts)
Angle Addition Postulate
If D is in the interior of ∠ABC, then ∠ABD + ∠DBC = ∠ABC