Understanding Lines and Triangles

Front

What is the definition of a line in geometry?

Back

A straight path that extends infinitely in both directions.

Front

What is a triangle?

Back

A polygon with three edges and three vertices.

Front

What is an angle?

Back

A figure formed by two rays with a common endpoint called the vertex.

Front

What are parallel lines?

Back

Lines in a plane that never meet and are always the same distance apart.

Front

What are perpendicular lines?

Back

Lines that intersect at a right angle (90 degrees).

Front

What is an acute angle?

Back

An angle that measures less than 90 degrees.

Front

What is a right angle?

Back

An angle that measures exactly 90 degrees.

Front

What is an obtuse angle?

Back

An angle that measures more than 90 degrees but less than 180 degrees.

Front

What is a line segment?

Back

A part of a line that has two endpoints.

Front

What is a ray?

Back

A part of a line that starts at one point and extends infinitely in one direction.