Geometry Chapter 1

Front 1

Postulate

Back 1

A line contains at least 2 points; a plane contains at least 3 points not all in one line; space contains at least four points not all in one plane.

Front 2

Postulate

Back 2

Through any 2 points there is exactly one line.

Front 3

Postulate

Back 3

Through any 3 points there is at least one plane, and through any three non collinear points there is exactly one plane.

Front 4

Postulate

Back 4

If two points are in a plane, then the line that contains the points is in that plane.

Front 5

Postulate

Back 5

If two planes intersect, then their intersection is a line.

Front 6

Theorem

Back 6

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

Front 7

Theorem

Back 7

Through a line and a point not in a line there is exactly one plane.

Front 8

Theorem

Back 8

If two lines intersect, then exactly one plane contains the lines.

Front 9

Protractor Postulate

Back 9

???

Front 10

Angle Addition Postulate

Back 10

If point b lies in the interior of angle aoc then m angle aob + m angle boc = m angle aoc

If angle aoc is a straight angle and b is any point not on line ac, then m angle aob and m angle boc = 180

Front 11

Segment Addition Postulate

Back 11

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

Front 12

Ruler Postulate

Back 12

The points on a line can be paired with the real numbers in such a way that any two points can have coordinates 0 and 1

Once a coordinate system has been chosen in this way, the distance between any two points equals the absolute value of the difference of their coordinates