Transcript 9-1 Points, Lines, & Planes in Space

9-1 Points, Lines, and
Planes in Space
Figure
Point
Line
Plane
Triangle
Cylinder
Dimensions
0
1
2
2
3
Point-Line-Plane Postulate
a. Unique Line Assumption-Through any 2 points,
there is exactly 1 line.
b. Number Line Assumption-Every line is a set of
points that corresponds to real numbers.
c. Dimension Assumption-A plane is 2-d, space is
3-d.
d. Flat plane assumption-2 points in a plane
means their line is in the plane also.
e. Unique Plane Assumption-Through 3
noncollinear points, there is exactly 1 plane.
f. Intersecting Planes Assumption-If 2 different
planes have a point in common, then their
intersection is a line.
Match each with the Point-LinePlane Postulate
•
•
•
•
Stability of a 3 legged stool (e)
A yardstick might show inches or feet (b)
The line joining 2 points on a kitchen table (d)
There is one straight route between San
Francisco and Los Angeles (a)
• The intersection of 2 walls in my classroom (f)
To draw 2 intersecting planes:
Draw 2 parallelograms that intersect and
draw a line where they cross.
*Planes have no thickness .