Lines, Line Segments, and Rays
Types of Lines
Polygons
Geometry Vocabulary
Angles
100

This is a straight line that goes on forever in both directions.

What is a line?

100

These lines are ALWAYS the same distance apart and NEVER INTERSECT.

What are parallel lines?

100
It has three sides and three angles.
What is a triangle?
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 point and an endpoint.

What is a line segment?

200

These lines will cross paths.

What are intersecting lines?

200
It has four sides and four angles.
What is a square?
200
A four sided polygon.
What is a quadrangle?
200
An angle that is smaller than 90 degrees.
What is an acute angle?
300

This has a starting point, but goes on forever in one direction.

What is a ray?

300

These lines are not currently crossing paths, but if you extend them out, they would.

What are intersecting lines?

300
It has five sides and five angles.
What is a pentagon?
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 a spot directly in the middle of a line. 

What is a midpoint?

400
An example is railroad tracks.
What are parallel lines?
400
It has six sides and six angles.
What is a hexagon?
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 dots on a line, line segment, and ray, and are usually named with a letter.

What are points?

500

An example is an intersection with traffic lights.

What are intersecting lines or perpendicular lines?

500
It has eight sides and eight angles.
What is an octagon?
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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