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Front-side Reverse-side
acute angle any angle measring between 0 degrees and 90 degrees
adjacent angles two angles sharing a commen vertex and side, but has no commen interior points
angle consists of two different rays that have the same initial point
angle addition postulate if C is in the interior of angle AOD, then m of angle AOC+m of angle COD=m of angle AOD
angle bisector a ray that divides the angle into two congruent angles
collinear points, segments, or rays that lie om the same line
complementary angles the sum of two angle measures is 90 degrees (each angle is the complement of the other)
congruent angles two angles with the same measure
congruent segments two segments with the same length
distance formula square root of (x2-x1) squared + (y2-y1) squared
exterior of an angle the angle between any side of a shape and a line extended from the next side
interior of an angle the area between the rays that make up an angle, and extending away from the vertex to infinity
intersecting lines coplaner lines that have exactly one point in common
line segment a segment of a number line where both endpoints stop the line from continueing in either direction (no arrowheads)
linear pair two adjacent angles whoses noncommen sides are opposite rays
Linear pair postulate if two angles form a linear pair, then they are supplementary (ie. the sun of their measures is 180 degrees)
midpoint bisects the segment into two shorter segments of equal length
midpoint the point that divides the segment into two congruent segments
midpoint formula (x1+x2 , y1+y2)
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2 2
oblique lines lines are oblique if they intersect and do not form right angles
obtuse angle any angle measuring between 90 degrees and 180 degrees
opposite rays if a letter© is between the two endpoints (A, B), than ray CA and ray CB are opposite
parallel lines coplaner lines that don’t intersect
perpendicular lines two lines that intersect to form a right angle
a line is perpendicular to a plane if it is perpendicular to each line in the plane that intersects it
Point, Line, and Plane Postulates
Postulate 10
if two distinct planes intersect, then their intersection is a line
Point, Line, and Plane Postulates
Postulate 5
through any two distinct points there exists exactly one line
Point, Line, and Plane Postulates
Postulate 6
a line contains at least two points
Point, Line, and Plane Postulates
Postulate 7
through any three noncollinear points there exists exactly one plane
Point, Line, and Plane Postulates
Postulate 8
a plane contains at least three noncollinear points
Point, Line, and Plane Postulates
Postulate 9
if two distinct points lie in a plane, then the line containing them lies in the plane
postulate 12 if two distinct lines intersect, then their intersection is exactly one point
postulate 13-parallel postulate if there is a line and a point not on the line, then there is exactly one line through the point parallel to the given line
postulate 14-perpendicular postulate if there is a line and a point not on the line, then there is exactly one line through the point perpendicular to the given line
Properties of Congruence
Reflexive Property
any geometric object is congruent to its self
Properties of Congruence
Symmetric Property
if one geometric object is congruent to a second, then the second object is congruent to the first.
Properties of Congruence
Transitive Property
if one geometric object is congruent to a second, and the second is congruent to a third, then the first object is congruent to the third object
Properties of Equality (a, b, c are real numbers)
Addition Property
if a=b, then a+c=b+c
Properties of Equality (a, b, c are real numbers)
Division Property
if a=b and c doesn’t =0, then a/c=b/c
Properties of Equality (a, b, c are real numbers)
Multiplication Property
if a=b, then ac=bc
Properties of Equality (a, b, c are real numbers)
Subtraction Property
if a=b, then a-c=b-c
Properties of Equality (let a, b, c be real numbers)
Reflexive Property
for ant real number a, a=a
Properties of Equality (let a, b, c be real numbers)
Sustitution Property
if a=b, then a may be substituted for b in any equation or expression
Properties of Equality (let a, b, c be real numbers)
Symmetric Property
if a=b, then b=a
Properties of Equality (let a, b, c be real numbers)
Transitive Property
if a=b and b=c, then a=c
ray a segment of a number line where one side has no arrowhead, and the other continues on forever.
right angle any angle equaling 90 degrees
segment addition postulate if B is between A and C, then AB+BC=AC
segment bisector a segmens, ray, line, or plane that intersects a segment at its midpoint
skew lines two lines that don’t lie on the same plane
straight angle any angle equaling 180 degrees
supplementary angles the sum of two angles measures is 180 degrees (each angle is the supplement of the other)
Thm 2.1; Congruent supplements thm if two angles are supplementary to the same angle or to congruent angles, then they are congruent
thm 2.2; congruent complements thm if two angles are complementary to the same angle or to congruent angles, then they are congruent
thm 2.3; vertical angles thm if two angles are vertical angles, then they are congruent
thm 3.1; transitivity of parallel lines if two lines are parrallel to the same line, then they are parallel to each other
thm 3.2; property of perpendicular lines if two coplaner lines are perpendicular to the same line, then they are parallel to each other
thm 3.3 if two lines are perpendicular, then they intersect to form four right angles
thm 3.4 all right angles are congruent
thm 3.5 if two lines intersect to form a pair of adjacent congruent angles, then the lines are perpendicular
transversal a line that intersects two or more coplaner lines at different points
vertical angles two angles whose sides form two pairs of opposite rays