Vocabulary 01

Question 1

line

Answer 1

A straight curve that has no width and no end.

Question 2

line segment

Answer 2

A part of a line that consists of two endpoints and

all points between the endpoints

Question 3

parallel lines

Answer 3

lines on the same plane that do not intersect

Question 4

acute angle

Answer 4

An angle whose measure is between

0 and 90 degrees

Question 5

obtuse angle

Answer 5

An angle whose measure is between

90 and 180 degrees

Question 6

polygon

Answer 6

Any simple, closed planar figure whose sides are

line segments.

Question 7

convex polygon

Answer 7

A polygon in which all interior angles have a measure less than or equal to 180 degrees.

Question 8

concave polygon

Answer 8

A polygon in which one or more interior angles have a measure greater than 180 degrees.

Question 9

equilateral polygon

Answer 9

A polygon whose sides all have equal length

Question 10

equiangular polygon

Answer 10

A polygon who’s angles all have equal measure.

Question 11

triangle

Answer 11

A polygon with three sides and whose sum of angles

equals 180 degrees.

Question 12

isosceles triangle

Answer 12

A triangle with at least two sides that are equal.

Question 13

scalene triangle

Answer 13

A triangle with all sides of different lengths.

Question 14

inverse operation

Answer 14

An operation which “undoes” another operation. Example: addition and subtraction are inverse operations. Also multplication and division are inverse operations.

Question 15

opposites

Answer 15

Two numbers with the same absolute value but

with different signs

Question 16

perimeter

Answer 16

The distance around the outside

of a closed, planar figure.

Question 17

chord

Answer 17

In a circle, a line segment whose

endpoints are on the circle.

Question 18

diameter

Answer 18

In a circle, the chord within a circle

that passes through the center of the circle.

Question 19

radius

Answer 19

In a circle, the distance from any point on a circle

to the center of the circle.

Question 20

circumference

Answer 20

The distance around a circle or

the perimeter of the circle.

Question 21

natural numbers

Answer 21

The set of numbers that we use to count objects or things. Also called positive integers.

Any member of the set {1, 2, 3 …}.

Question 22

real numbers

Answer 22

The set of all numbers on a number line

(rational and irrational).

Question 23

whole numbers

Answer 23

Any number of the set {0, 1, 2, 3, …}

Question 24

integers

Answer 24

Any member of the set

{…, -3, -2, -1, 0, 1, 2, 3, …}

Question 25

irrational number

Answer 25

Any number that cannot be writen as a quotient of integers. For example, the numbers π and square root of 2 are irrational numbers.

Question 26

rational number

Answer 26

Any number that can be written as a/b

(where a and b are integers and b is not zero).

When written as decimals,

rational numbers terminate or repeat.