Mathematics For The Elementary School Teacher

Front 1

Fibonacci Sequence

Back 1

1, 2, 3, 5, 8, 13, 21, ... The next term is the sum of the two preceding terms.

Front 2

"geometry"

Back 2

"Earth measure". The Eqyptians used it to redraw land boundaries that were washed away each year by the Nile flooding.

Front 3

Point

Back 3

A location that has no length, width, or height.

Front 4

Line

Back 4

A set of points in a straight, unlimited length with no thickness or endpoints.

Front 5

Plane

Back 5

A set of points in a flat surface that has no thickness and no edges.

Front 6

Collinear

Back 6

Points that can be contained in one line.

Front 7

Intersect

Back 7

Divide (something) by passing or lying across it

Front 8

Parallel

Back 8

Two lines in a plane that do not intersect or meet are called parallel lines.

Front 9

Concurrent

Back 9

Two or more lines are said to be concurrent if they intersect in a single point.

Front 10

Line Segment

Back 10

The set of points A and B and all the points between A and B.
(Drawn A or B with a bar above)

Front 11

Ray

Back 11

The point A and all the points on the ray on the same side of A as point B. (Drawn A with an arrow pointed to the right)

Front 12

Angle

Back 12

The union of two noncollinear rays that have a commom endpoint. (Written with an angle symbol preceding the three points with the vertex in the center)

Front 13

congruent segments

Back 13

Two segments are congruent segments if they have the same length.

Front 14

bisector of a segment

Back 14

Any point, segment, ray, line, or plane that contains the midpoint of a segment.

Front 15

degree measure (m) of the angle

Back 15

The amount of rotation

Front 16

Straight Angle

Back 16

An angle of 180º.

Front 17

Reflex Angle

Back 17

An angle that is more than 180º but less than 360º.

Front 18

Zero Angle

Back 18

An angle with no rotation.

Front 19

Interior

Back 19

A set of points located inside an angle.

Front 20

Exterior

Back 20

A set of points not located in or on an angle.

Front 21

angle bisector

Back 21

The ray in the interior of an angle that forms two congruent angles.

Front 22

right angle

Back 22

An angle with a measure of 90º.

Front 23

acute angle

Back 23

An angle which has a measure between 0º and 90º.

Front 24

obtuse angle

Back 24

An angle which has a measure between 90º and 180º.

Front 25

Complementary angle

Back 25

An pair of angles whose measures have a sum of 90º.

Front 26

supplementary angles

Back 26

A pair of angles whose meausres have a sum of 180º.

Front 27

adjacent angles

Back 27

Two angles that have the same vertex and a common side, but have no common interior points. (Like an angle inside an angle)

Front 28

linear pair of angles

Back 28

A pair of adjacent angles with two noncommon sides on the same line.

Front 29

vertical angles

Back 29

A pair of angles that are formed by two intersecting lines and that are not a linear pair of angles.

Front 30

perpendicular

Back 30

Two lines that intersect to form four right angles.

Front 31

perpendicular bisector

Back 31

A line that is perpendicular to the segment and which divides it into two congruent segments.

Front 32

nonsimple closed curve

Back 32

A curve that does not cross itself.

Front 33

simple closed curve

Back 33

A connected curve that does not cross itself and ends at the same point where it begins.

Front 34

circle

Back 34

A special type of simple closed curve in which all of the points in the curve are in one plane and are equidistant from a given point in the same plane (the center of the circle).

Front 35

chord

Back 35

a segment whose endpoints are on the circle.

Front 36

diameter

Back 36

a chord with on endpoint at the center of the circle and one endpoint on the circle

Front 37

radius

Back 37

a segment with one endpoint at the center of the circle and one endpoint on the circle

Front 38

polygon

Back 38

a closed curve created from the union of segments meeting only at endpoints such that (1) at most, two segments meet at one point, and (2) each segment meets exaxtly two other segments at their endpoints.

Front 39

nonsimple polygon

Back 39

has a least one pair of segments that intersect in a point other than their endpoints.

Front 40

simple polygon

Back 40

has not intersections

Front 41

simple convex polygon

Back 41

searifies the property that for each pair of points P and Q inside the polygon, the line PQ lies inside the polygon.

Front 42

simple concave polygon

Back 42

a nonconvex polygon that has at least one pair of points P and Q that can be be positioned inside the polygon so the part of the line PQ lies outside the polygon.

Front 43

n-gon

Back 43

if the whole number n represents the number of sides of a polygon

Front 44

interior angle (of a polygon)

Back 44

formed by two sides of the polygon that have a common vertex

Front 45

regular polygon

Back 45

a simple polygon with all sides congruent and all interior angles congruent

Front 46

triangle

Back 46

a 3-sided polygon

Front 47

quadrilateral

Back 47

a 4-sided polygon

Front 48

pentagon

Back 48

a 5-sided polygon

Front 49

hexagon

Back 49

a 6-sided polygon

Front 50

haptagon

Back 50

a 7-sided polygon

Front 51

octagon

Back 51

an 8-sided polygon

Front 52

nonagon

Back 52

a 9-sided polygon

Front 53

decagon

Back 53

a 10-sided polygon

Front 54

dodecagon

Back 54

a 12-sided polygon

Front 55

Triangle ABC

Back 55

The union of three segments determined by three noncollinear points A, B, and C, which are the vertices of the triangle, and lines AB, BC, and AC are the sides of the triangle.

Front 56

median

Back 56

a segments from a vertex of a triangle to the midpoint of the side of the traingle opposite that vertex

Front 57

altitude

Back 57

a triangle a segment from a vertex of a traingle perpendicular to a line containing the side of triangle opposite that vertex

Front 58

equilateral triangle

Back 58

all sides congruent: equiangular

Front 59

isosceles triangle

Back 59

at least one pair of congruent sides: an isosceles triangle

Front 60

scalene triangle

Back 60

no congruent sides

Front 61

right triangle

Back 61

one right angle

Front 62

acute triangle

Back 62

all acute angles

Front 63

obtuse triangle

Back 63

one obtuse angle

Front 64

trapezoid

Back 64

exactly one pair of opposite sides parallel

Front 65

kite

Back 65

at least two pairs of adjacent sides congruent, no side used twice in the pairs

Front 66

parallelogram

Back 66

pairs of opposite sides parallel and the same length

Front 67

rhombus

Back 67

all sides the same length and opposite sides parallel

Front 68

rectangle

Back 68

opposite sides parallel and the same length, all angles are right angles

Front 69

square

Back 69

all sides the same length; all angles are right angles

Front 70

square

Back 70

all sides the same length; all angles are right angles