Intro to Geometry

Question 1

line

Answer 1

straight line that extends in 2 directions without end, w 2 arrowheads to show it

Question 2

segment

Answer 2

part of line that consists of 2 points called endpoints, all points on line are end points

Question 3

ray

Answer 3

part of line that consists of a point called an initial point, all points on the line extend in 1 direction

Question 4

parallel lines

Answer 4

two lines that don’t intersect and extend next to each other

Question 5

perpendicular lines

Answer 5

2 lines that cross to form 90º angle

Question 6

congruent

Answer 6

same measurement for 2 things

Question 7

midpoint (of a segment)

Answer 7

point that splits segment into 2 congruent segments

Question 8

segment bisector

Answer 8

segment that intersects another segment at its midpoint

Question 9

collinear points

Answer 9

points that lie on the same line

Question 10

angle

Answer 10

has 2 different rays w/ same initial point, rays are on the sides of the angle, initial point is vertex

Question 11

adjacent angle

Answer 11

2 angles w/ common vertex and side but no common interior points

Question 12

right angle

Answer 12

angle w/ 90º measurement

Question 13

acute angle

Answer 13

angle w/ measure between 0º and 90º

Question 14

obtuse angle

Answer 14

angle w/ measure between 90º and 180º

Question 15

straight angle

Answer 15

angle w/ 180º measurement

Question 16

angle bisector

Answer 16

ray that splits an angle into 2 adjacent angles that are congruent

Question 17

vertical angles

Answer 17

2 angles whose sides form 2 pairs of opposite rays

Question 18

linear pair

Answer 18

2 adjacent angles whose non common slides are opposite

Question 19

complementary angles

Answer 19

2 angles whose measures have sum of 90º

Question 20

supplementary angles

Answer 20

2 angles whose measure have sum of 180º

Question 21

polygon

Answer 21

shape w/ 3 or more sides (no 2 sides with common end point are collinear), each side intersects

Question 22

perimeter of polygon

Answer 22

sum of lengths of its sides

Question 23

regular polygon

Answer 23

polygon that is equilateral and equiangular

Question 24

triangle

Answer 24

shape formed by 3 segments joining 3 non collinear points, called vertices

Question 25

equilateral triangle

Answer 25

triangle w/ no congruent sides

Question 26

scalene

Answer 26

triangle w/ no congruent sides

Question 27

isosceles triangle

Answer 27

triangle w/ at least 2 congruent sides

Question 28

right triangle

Answer 28

triangle w/ one right angle

Question 29

triangle sum theorem

Answer 29

the sum of the measures of the interior angles of a triangle is 180º

Question 30

altitude of a triangle

Answer 30

perpendicular segment from a vertex of a triangle to the opposite side or to the line that contains the opposite side

Question 31

reflexive property

Answer 31

a=a

Question 32

transitive property

Answer 32

if a=b and b=c, then a=c

Question 33

segment addition postulate

Answer 33

if b is between a and c, then ab + bc = ac. if ab + bc = ac, then b is between a and c

Question 34

angle addition postulate

Answer 34

if p is in the interior of

Question 35

through any 2 points there is

Answer 35

a unique line

Question 36

through any 3 points there is

Answer 36

a unique plane

Question 37

linear pair postulate

Answer 37

if 2 angles from a linear pair, they are supplementary (90º)

Question 38

vertical angles theorem

Answer 38

vertical angles are congruent

Question 39

point

Answer 39

no dimension, represented by small dot