Postulates And Theorems
P1-Ruler Postulate. P2-seg. add. postulate.
P3-Protractor postulate. P4-angle
add. postulate. P5- A line contains at
least two points; a plane contains at
least 3 points not all in one line;
space contains at least 4 pints not all in
one plane. P6- Through any 2
points their is excatly 1 line. P7-Through any 3
points there is at least one
plane , and through any three noncollinear points
there is exactly one plane.
P8- If two points are in a plane the the line that
contains the points is in
that plane. P9-If two intersect, then their
intersection is a line. T1-1-If
tow lines intersect then they intersect in
exactly one point. T1-2-Through a
line and a point not in the line there is
exactly one plane. T1-3- If 2 lines
intersect then exactly one plane contains
the lines. Properties of equality
Add. Prop-if a=b and c=d then a+c=b+d
Subtraction Prop-if a=b and c=d
then a-c=b-d Mult. Prop- if a=b then ca=cb Div
Prop.-if a=b and c doesnt
= 0 then a/c=b/c Substitution prop- if a=b then either
a or b may be
substituded for the other in any equation. Reflexive
Property-a=a
Symmetric Property- if a=b then b=a Transitive Prop.-if a=b
and b=c then a=c.
Properties of Congruence Reflexive Prop-Line DE is
congruent to line DE. angle
D=angle D Symmetric Prop.- Line DE=FG then
FG=DE. angle D=F then angle F=D.
Transitive Prop.- Line DE is congruent
to line FG and line FG is congruent to JK
then line DE is congruent to JK.
Distributive Prop.-a(b+c)=ab+ac T2-1- IF M is
the midpoint of line ab then am
= half ab and mb = half ab line amb. T2-2- If
ray bx is the bisector of angle
abc then m of angle abx=half the measure of
angle abc and measure of angle
xbc =half m angle abc. T2-3- Vert. angle are
congruent. T2-4- If 2 lines are
perpendicular then they form congruent adjacent
angles. T2-5- IF 2 lines form
congruent adjacent angles then the lines are
perpendicular. T2-6- If the
exterior sides of two adjacent acute angles are
perpendicular then the angles
are complementary. T2-7- IF 2 angles are
supplements of congruent angles then
the 2 angles are congruent. T2-8- IF 2
angles are complements of congruent
angles then the 2 angles are congruent.
T3-1- IF 2 parallel planes are
cut bty a 3rd plane then the lines of
intersection are parallel. P10- If 2
parallel lines are cut by a transversal,
then corresponding angles are
congruent. T3-2- IF 2 parallel lines are cut by a
transversal then alternate
interior angles are congruent. T3-3- IF 2 parallel
lines are cut by a
transveral then same side interior angles are supplementary.
T3-4-If a
transversal is perpendicular to one of 2 parallel lines then it
is
perpendicular to the other one also. P11- IF 2 lines are cut by a
transversal
and corresponding angles are congruent then the lines are
parallel. T3-5- If 2
lines are cut by a transversal and alternate interior
angles are congrunt then
the lines are parallel. T3-6- If 2 lines are cut by
a transversal and same side
interior angles are supplementary then the lines
are parallel. T3-7- In a plane
2 lines perpendicular to the same line are
parallel. T3-8- Through a piont
outside a line there is exactly one line
parallel to the given line. T3-9-
Through a point outside a line there is
exactly one line perpendicular to the
given line. T3-10- Two lines parallel
to a 3rd line are parallel to each other.
T3-11- The sum of the measures
of the angles of a triangle is 180. C1- If 2
angles of one triangle are
congruent to 2 angles of another triangle then the
3rd angless are
congruent. C2- Each angle of an equianglular triangle has
measure 60. C3- In
a triangle there can be at most one right angle or obtuse
angle. C4- the
acute of a right triangle ar complementary. T3-12- The measure of
an exterior
angle of a triangle equals the sum of the measure of the 2 remote
interior
angles. Scalene- no sides congruent. Isosceles- at least 2 sides
congruent.
Equilateral- all sides congruent. Acute- 3 acute angles. Obtuse- 1
obtuse
angle. Right- 1 right angle. Equilangular- all angles congruent. Ways
To
prove to lines are parallel. 1. Show that a pair of corresponding angles
are
congruent. 2. Show that a pair of alternate interior angles are
congruent. 3.
Show that a pair of same side interior angles are
supplementary. 4. In a plane
show that both lines are perpendicular to a
third line. 5. Show that both lines
are parallel to a third line. Alternate
Interior angles- are 2 nonadjacent
interior angles on opposite sides of the
transversal. Z Same Side Interior
angles- are 2 interior angles on the same
side of the transversal. U
Corresponding angles- are 2 angles in
corresponding postitions relative to the 2
lines.