Unit 1

Question 1

Point

Answer 1

A point indicates a location and has no size. Represented a by a dot and a capital letter, such as A .

Question 2

Line

Answer 2

A straight path that extends in two opposite directions without end and has no thickness. A line contains infinitely many points. Named by any two points on the line, such as AB (read “line AB ”) or BA, or by a single lowercase letter, such as line / .

Question 3

Plane

Answer 3

A flat surface that extends without end and has no thickness. A plane contains infinitely many lines.You can name a plane by a capital letter, such as plane P, or by at least three points in the plane that do not all lie on the same line, such as plane ABC.

Question 4

Coplanar

Answer 4

Points that lie on the same plane, all points of any line are coplanar.

Question 5

Collinear

Answer 5

Points that lie on the same line

Question 6

Geometric Figure

Answer 6

Set of points

Question 7

Space

Answer 7

The set of all points in three dimensions.

Question 8

Segment

Answer 8

Part of a line that consists of two endpoints and all points between them. name a segment by its two endpoints, such as AB (read “segment AB ”) or BA

Question 9

Ray

Answer 9

Part of a line that consists of one endpoint and all the points of the line on one side of the endpoint. You can name a ray by its endpoint and another point on the ray, such as AB > (read “ray AB ”). The order of points indicates the ray’s direction.

Question 10

Opposite Rays

Answer 10

Two rays that share the same endpoint and form a line. Name opposite rays by their shared endpoint and any other point on each ray, such as CA > and CB > .

Question 11

Postulate/Axiom

Answer 11

An accepted statement of fact used to justify answers in proofs

Question 12

Postulate 1-1

Answer 12

Through any 2 points there is exactly one line that passes both of them

Question 13

Postulate 1-2

Answer 13

If two distinct lines intersect, then they intersect in exactly one point.

Question 14

Postulate 1-3

Answer 14

If two distinct planes intersect, then they intersect in exactly one line.

Question 15

Postulate 1-4

Answer 15

Through any three noncollinear points there is exactly one plane.

Question 16

Ruler Postulate/ 1-5

Answer 16

Every point on a line can be paired with a real number. This makes a one-to-one correspondence between the points on the line and the real numbers. The real number that corresponds to a point is called the coordinate of the point.

Question 17

Segment Addition Postulate

Answer 17

If three points A , B , and C are collinear and B is between A and C , then AB + BC = AC

Question 18

Equal sign vs. Congruent Sign

Answer 18

Equal sign is used for the measure of things, whereas congruent is used for comparing the shape or figure itself

Question 19

Angle

Answer 19

A figure formed with 2 rays and an endpoint, the rays are the “sides” and the endpoint is the “vertex”

Question 20

Interior of an Angle

Answer 20

The region containing all of the points between the two sides of the angle.

Question 21

Exterior of an Angle

Answer 21

The region containing all of the points outside of the angle.

Question 22

Protractor Postulate

Answer 22

Consider OB > and a point A on one side of OB > . Every ray of the form OA > can be paired one to one with a real number from 0 to 180.

Question 23

Acute Angle

Answer 23

A measure less than 90

Question 24

Right Angle

Answer 24

A 90 degree measure

Question 25

Obtuse Angle

Answer 25

A measure more than 90 degrees

Question 26

Straight Angle

Answer 26

A measure of 180 degrees

Question 27

Congruent Angles

Answer 27

Angles with the same measure

Question 28

Postulate 1-8/Angle Addition Postulate

Answer 28

If point B is in the interior of ∠AOC , then m ∠AOB + m ∠BOC = m ∠AOC
The 2 inside angles in a big angle add up to make the big angle.

Question 29

Adjacent Angles

Answer 29

Two coplanar angles with a common side, a common vertex, and no common interior points.

Question 30

Vertical angles

Answer 30

Two angles whose sides are opposite rays.

Question 31

Complementary angles

Answer 31

Two angles whose measures have a sum of 90. Each angle is called the complement of the other.

Question 32

Supplementary angles

Answer 32

Two angles whose measures have a sum of 180. Each angle is called the supplement of the other.

Question 33

Unmarked Diagram Conclusions

Answer 33

• Angles are adjacent.
• Angles are adjacent and supplementary.
• Angles are vertical angles.

Question 34

Unmarked Diagram Conclusions that can’t be made

Answer 34

*Angles or segments are congruent.
*An angle is a right angle
*Angles are complementary.

Question 35

Linear Pair Postulate/1-9

Answer 35

If two angles form a linear pair, then they are supplementary.

Question 36

Linear Pair

Answer 36

A pair of adjacent angles whose noncommon sides are opposite rays. The angles of a linear pair form a straight angle.

Question 37

Straightedge

Answer 37

A ruler with no markings on it

Question 38

Compass

Answer 38

A geometric tool used to draw circles and parts of circles called arcs

Question 39

Construction

Answer 39

A geometric figure drawn using a straightedge and a compass.

Question 40

Perpendicular Lines

Answer 40

Two lines that intersect to form a right angle

Question 41

Perpendicular bisector

Answer 41

A segment is a line, segment, or ray that is perpendicular to the segment at its midpoint.

Question 42

Midpoint on a number line

Answer 42

The coordinate of the midpoint M of AB is (a + b)/2

Question 43

Midpoint in the coordinate plane

Answer 43

Given AB where A ( x 1 , y 1 ) and B ( x 2 , y 2 ) , the coordinates of the midpoint of AB are M ( x 1 + x 2)/2 , (y 1 + y 2)/2.

Question 44

Distance Formula

Answer 44

d = The square root of
( x 2 -x 1 ) squared + ( y 2 -y 1) squared