Honors Geometry - Section 1.1 - Points, Lines and Planes

Undefined Terms

Words without formal definitions

How many dimensions do points have?

None

What symbol represents a point?

A dot

How many dimensions does a line have?

One

All lines are represented by what?

Lines or Arrowheads

How much do lines extend?

Infinitely in both directions

How does one name a line?

By using 2 points on the line

Through any two points there is exactly how many lines?

One

How many dimensions are on a plane?

2 dimensions

All planes are represented by what?

A shape that looks like a floor or a wall

How big do all planes extend in every direction?

infinitely

How does one name a plane?

Buy using any 3 points that aren’t on the same line within the plane

Through any three points not on the same line there is exactly how many planes?

One

What are collinear points

Points that lie on the same line

What are coplanar points

Points on the same plane

What are defined terms

Terms that can be described

Line segments have definite…?

Beginnings and ends

What are the beginnings and ends called on na line segment

end points

To name a segment, what does one do?

They use two letters for each end point

A ray begins where?

At an endpoint

How long does ray extend from its endpoint in one direction?

Infinitely

What does one do to name a ray?

One must name the endpoint first and then name any other point on the ray

What are opposite rays?

Two collinear rays with the same end point

What directions do opposite rays extend in?

Opposite directions

What is an intersection

The set of points that two or more geometric figures have in common

How many times can two lines intersect

Once, 0 times or infinitely many times

How many times can a line and a plane intersect?

Once, 0 times or infinitely many times

How many times can two planes intersect?

0 times or infinitely many times