Chapter 1 Vocabulary

Question 1

Collinear set of points

Answer 1

a set of points all of which lie on the same straight line

Question 2

Noncollinear set of points

Answer 2

a set of three or more points that do not all lie on the same straight line.

Question 3

Distance between two points on the real number line

Answer 3

the absolute value of the difference of the coordinates of the two points

Question 4

B is between A and C

Answer 4

AB + BC = AC

Question 5

Line segment

Answer 5

a set of points consisting of two points on a line, called endpoints, and all of the points between the endpoints.

Question 6

Length or Measure of a Line Segment

Answer 6

The distance between its endpoints

Question 7

Congruent Segments

Answer 7

segments that have the same measure

Question 8

Midpoint of a line segment

Answer 8

a point of that line segment that divides the segment into two congruent segments

Question 9

Bisector or a line segment

Answer 9

any line, or subset of a line, that intersects the segment at its midpoint

Question 10

Half-line

Answer 10

a set of points on one side of a point

Question 11

Ray

Answer 11

a half-line including the endpoint

Question 12

Opposite Rays

Answer 12

Rays that are in the same line that have the same endpoint

Question 13

angle

Answer 13

two rays having the same endpoint

Question 14

straight angle

Answer 14

an angle that measures 180 degrees

Question 15

acute angle

Answer 15

an angle whose measureis greater than zero and less than 90

Question 16

right angle

Answer 16

an angle whose measure is exactly 90 degrees

Question 17

obtuse angle

Answer 17

an angle whose measure is greater than 90 degrees and less than 180 degrees

Question 18

Congruent angles

Answer 18

angles that have the same measure

Question 19

Bisector of an angle

Answer 19

a ray whose endpoint is the vertex of the angle, and that divides that angle into two congruent angles

Question 20

Perpendicular lines

Answer 20

two lines that intersect to form right angles

Question 21

Distance from a point to a line

Answer 21

the length of the perpendicular from the point to the line

Question 22

Polygon

Answer 22

a closed figure in the plane

Question 23

triangle

Answer 23

a polygon that has no congruent sides

Question 24

Scalene triangle

Answer 24

a triangle that has no congruent sides

Question 25

Isosceles triangle

Answer 25

a triangle that has two congruent sides

Question 26

Equilateral triangle

Answer 26

a triangle that has three congruent sides

Question 27

acute triangle

Answer 27

a triangle that has three acute angles

Question 28

right triangle

Answer 28

a triangle that has one 90 degree angle

Question 29

obtuse triangle

Answer 29

a triangle that has one obtuse angle

Question 30

Equiangular triangle

Answer 30

a triangle that has all three angles 60 degrees each

Question 31

The Undefined Terms

Answer 31

Point, Line, Plane, Set