Lines and Angles Flashcards
Postulate or Axiom
Rules that are accepted without proof
Ruler Postulate
The points on a line can be matched one-to-one with the real numbers - real numbers that correspond to a point are called coordinantes.
Segment Addition Postulate
if we have a line segment AC and a point B within it, the sum of the lengths of the segments AB and BC will give the total length of AC.
Protractor Postulate
The rays in a half rotation can be numbered from 0 to 180. The
measure of ÐAOB is equal to the absolute value of the difference between
the real numbers for lines OA and OB.
Angle Addition Postulate
If P is in the interior of angle RST then the measure of angle RSP + the measure of angle PST = measure of angle RST.
Line divides one triangle into two triangles each side adds up to each other
Distance Formula
Distance = SQRT(x2 - x1)^2 + (y2 - y1)^2
Acute Angle Definition
An angle is acute IFF it is less than 90 degrees
Right Angle Definition
An angle is right IFF it is 90 degrees
Obtuse Angle Definition
An angle is obtuse IFF it is more than 90 degrees and less than 180
Straight Angle Definition
An angle is straight IFF it is 180 degrees
Adjacent Angles Definition
Two angles are said to be adjacent IFF they share a common vertex and side but have no common interior points.
Congruent Angles “Definition” no IFF
Angles that have the same measure are called congruent – angles are congruent IFF they have the same measure.
Midpoint Definition
A point is a midpoint of a line segment IFF it divides the line segment into two equal segments. (each side of the midpoint is equal)
Bisect Definition
A line bisects an angle IFF it divides the angle into two adjacent angles that are congruent (two equal angles)
Trisecting splits an angle into three equal parts
Addition Property of Equality
x-7 = 4
+7. +7.
x = 11