Lines, rays and planes are all around us. Let’s look at each one and see if we can find examples in our environment.

What are lines?

Lines are long, thin continuous marks.

We name and identify lines by using points on the lines.

A F

AF

G H

GH

There are 3 main types of lines.

What are parallel lines?

Parallel lines are always the same distance apart and never touch.

Can you name parallel lines in the diagram below?

A B

C

D

E

F

G HAG and BH

CE and DF

What are perpendicular lines?

Perpendicular lines are lines that intersect (cross) and make 4 right angles.

Can you name perpendicular lines in the diagram below?

A

B C

D E

FAF and BC

AF and DE

What are intersecting lines?

Intersecting lines cross one another but never form right angles. Intersecting lines can resemble an ‘X’.

Can you name intersecting lines in the diagram below?

A

F

C

E

D

B

CD and AE

CD and BF

What are rays?Rays are lines that have a definite starting point but no end. Rays continue on endlessly in one direction.

Can you name any rays in the diagram below?

A

F

ED

CB

FA and ED

What is a plane? (We are not talking about the one that flys in the sky).

A plane is a flat surface. It is named by at least 3 points. A

B

C

This is plane ABC.

Look around the classroom. Do you see any planes?

Chalkboard

Top of Desk

Floor

Wall

Ceiling

Door

Window

Book Cover

Paper

Dry Erase Boards

Can you find any parallel lines in the picture?

Are there any perpendicular lines in this picture?

Do you see any intersecting lines in these pictures?

What types of lines do can you find in these pictures?