Hhs Geometry Vocab. First Semester 1

Front 1

Points that lie on the same line

Back 1

Collinear

Front 2

Flat surface that has no thickness, extends forever

Back 2

Plane

Front 3

Straight path with no thickness, extends forever

Back 3

Line

Front 4

A location that has no size

Back 4

Point

Front 5

Two rays that have a common endpoint and form a line

Back 5

Opposite Rays

Front 6

Point at the end of a segment or the start of a ray

Back 6

Endpoint

Front 7

Part of a line, starts at an endpoint, extends forever in one direction

Back 7

Ray

Front 8

Part of a line that has 2 endpoints and can be measured

Back 8

Line Segment

Front 9

Two congruent angles across from each other when two lines intersect

Back 9

Vertical Angles

Front 10

Two angles with a common vertex and a common side

Back 10

Adjacent Angles

Front 11

Pair of adjacent angles that form a line

Back 11

Linear Pair

Front 12

Two angles with measures that have a sum of 90 degrees

Back 12

Complementary Angles

Front 13

Two angles with measures that have a sum of 180 degrees

Back 13

Supplementary Angles

Front 14

A ray that splits one angle into 2 congruent angles

Back 14

Angle Bisector

Front 15

Lines that never intersect; slopes are equal

Back 15

Parallel Lines

Front 16

Two lines that intersect to form 4 right angles; slopes are opposite reciprocals

Back 16

Perpendicular Lines

Front 17

Points or lines that lie on the same plane

Back 17

Coplanar

Front 18

A line that intersects 2 or more lines at different points

Back 18

Transversal

Front 19

Same size and same shape

Back 19

Congruent

Front 20

The prediction reached by inductive reasoning

Back 20

Conjecture

Front 21

The false example to show that a conjecture is not true

Back 21

Counterexample

Front 22

In a conditional statement, the part of the statement that immediately follows the word then

Back 22

Conclusion

Front 23

In a conditional statement, the part of the statement that immediately follows the word if

Back 23

Hypothesis

Front 24

Reasoning that allows you to reach a conjecture based on a number of specific examples or past events; assumption

Back 24

Inductive Reasoning

Front 25

Reasoning that uses facts, rules, definitions, or properties to make a conclusion

Back 25

Deductive Reasoning

Front 26

A point in the middle of a segment that is equal distances from each endpoint

Back 26

Midpoint

Front 27

Rate of change; rise over run

Back 27

Slope

Front 28

Length of a line segment

Back 28

Distance

Front 29

Triangle with all congruent angles.

Back 29

Equiangular Triangle

Front 30

Triangle with all angles less than 90 degrees.

Back 30

Acute Triangle

Front 31

Triangle with one angle greater than 90 degrees.

Back 31

Obtuse Triangle

Front 32

Triangle with at least two congruent sides.

Back 32

Isosceles Triangle

Front 33

Triangle with an angle equal to 90 degrees.

Back 33

Right Triangle

Front 34

Triangle with all congruent sides.

Back 34

Equilateral Triangle

Front 35

Triangle with no congruent sides.

Back 35

Scalene Triangle

Front 36

A line or segment that passes through the midpoint of a side of a triangle and is perpendicular to that side.

Back 36

Perpendicular Bisector

Front 37

A segment that connects a vertex of a triangle to the midpoint of the opposite side.

Back 37

Median

Front 38

A segment that bisects an angle of a triangle and then intersects the opposite side of the triangle.

Back 38

Angle Bisecctor

Front 39

A segment that is perpendicular to a side of a triangle, and it intersects the vertex opposite that side, also known as the height.

Back 39

Altitude