Geometry Theorem Flashcards
Segment Addition Postulate
Little Segment + Little Segment= Big Segment
Addition Property
If x=y, then x+a=y+a (add on both sides)
Angle Add. Post
m< + m<=180 OR Little < + Little <= Big <
Subtraction Property
If x+a=y+a, then x=y (subtract on both sides)
Substitution Property
Put something in place of something else
Reflexive Property
x=x
Transitive Property
If 1st=2nd and 2nd=3rd, then 1st=3rd
Def. of Comp Angles
If <’s are Comp, then <+<=180
Def. of Perp Lines
If perp, then m<=90
Symmetric Property
If x=y then y=x
Division Property
If a/c =b/c, then c doesn’t = 0 (divide on both sides)
Multiplication Property
If a=b then ac=bc (multiply on both sides)
Distributive Property
x(y=w)-xy+xw
Def. of Midpoint
If Midpoint, then segment=segment
Midpoint Theorem
If Midpoint, then little segment= 1/2 big segment
Def. of Supp Angles
If supp, then m<+m<=180
Def. of Angle Bisector
If ray bisects <, then angle=angle
Angle Bisector Theorem
If ray bisects <, then little <=1/2 big <
Vertical Angle Theorem
<1 is congruent to <4 (<1 and <4 are not adjacent, they are just opposites.)
If Ex, sides of two adjacent angles are perpendicular, then the angles are complementary
If perp, then comp
If 2 lines are perpendicular, they form congruent adjacent angles
If perp, then < is congruent to <
If 2 lines from congruent adjacent angles, then the lines are perp
If < is congruent to <, then they are perp
Congruent Supplements Theorem
If <1 is supp to <2 and <3 is supp
Congruent Complements Theorem
If <1 is comp to <2 and <3 is comp to <2
Def. of Congruence
If m< = m<, then < is congruent to <
Def. of Right Angle
If right <, then m<=90
Def. of Segment Bisector
If segment bisects segment, then midpoint
