Lines, Line Segments, and Rays
Types of Lines
Properties of Parallel Lines
Geometry Vocabulary
Angles
100
This is a straight line that goes on and on in both directions.
What is a line?
100

These lines are the same distance apart infinitely.

What are parallel lines?

100

Two non-adjacent supplemental angles on the same-side of the transversal; within parallel lines.

What are same-side interior angles?

100
A 2 dimensional figure with three or more sides that is closed.
What is a polygon?
100
A 90 degree angle.
What is a right angle?
200
This looks like a line, but has a beginning and end.
What is a line segment?
200
These lines will cross.
What are intersecting lines?
200

Two non-adjacent congruent angles on opposite sides of the transversal; within parallel lines.

What alternate interior angles?

200

A four sided polygon.

What is a quadrilateral?

200
An angle that is smaller than 90 degrees.
What is an acute angle?
300
This has a starting point, but goes on and on in one direction.
What is a ray?
300
These lines intersected at a 90 degree angle

What are perpendicular lines?

300

If a transversal intersects two parallel lines, then alternate exterior angles are...

What are congruent?

300
One of the line segments that make up a polygon.
What is a side?
300
An angle that is bigger than 90 degrees.
What is an obtuse angle?
400
This is named for the starting point and another point somewhere along the way and in that order.
What is a ray?
400
An example is railroad tracks.
What are parallel lines?
400

If a transversal intersects two parallel lines, then same-side exterior angles are...

What are supplementary?

400
The corner, or point at which line segments meet in a polygon.
What is a vertex?
400
A triangle with all sides equal.
What is an equilateral triangle?
500

These are stops along the way of a line, line segment, and ray, and are usually named with a letter.

What are points?

500

This type of line crosses 2 parallel lines at 2 points

What is a transversal?

500

Two angles in the same positions are congruent on the parallel lines.

What are corresponding angles?

500
A quadrilateral with two pairs of opposite and parallel sides.
What is a parallelogram?
500
A triangle with two sides the same length.
What is an isosceles triangle?
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