Lines, Angles, Triangles and Quadrilaterals

Front

What is an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

What is an obtuse angle?

Back

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

Front

What is a right angle?

Back

A right angle is an angle that measures exactly 90 degrees.

Front

What is a reflex angle?

Back

A reflex angle is an angle that measures more than 180 degrees but less than 360 degrees.

Front

What are parallel lines?

Back

Parallel lines are lines that never meet and are always the same distance apart.

Front

What are perpendicular lines?

Back

Perpendicular lines are lines that intersect at a right angle (90 degrees).

Front

What are intersecting lines?

Back

Intersecting lines are lines that cross each other at any angle.

Front

What is an acute triangle?

Back

An acute triangle is a triangle where all three angles are acute (less than 90 degrees).

Front

What is an obtuse triangle?

Back

An obtuse triangle is a triangle that has one angle that is obtuse (more than 90 degrees).

Front

What is a right triangle?

Back

A right triangle is a triangle that has one right angle (90 degrees).