Angles, Lines, Vocabulary

What is a line?

• A figure formed by two rays that share the same endpoint

• A figure with one endpoint that extends endlessly in one direction

• A figure that has no thickness and extends endlessly in both directions

• A part of a line that has two endpoints

What is the correct notation for this ray?

• 
• 
• 

An angle with 90 degrees:

The point where two or more lines, line segments, or rays meet to form an angle: 

Two adjacent angles that add up to 90 degrees:

Two adjacent angles that add up to 180 degrees: 

A straight figure extending infinitely in both directions:

A portion of a line having a starting and ending point:

A portion of a line with a starting point but no end point (continues infinitely in one direction):

An angle whose measure is less than 90 degrees: