Classify 2-D Shapes by Angles and Lines

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

How many obtuse angles can a triangle have?

Back

A triangle can have no obtuse angles, one obtuse angle, or two obtuse angles, but not three.

Front

What is a rectangle?

Back

A rectangle is a four-sided shape (quadrilateral) with exactly two pairs of parallel sides and four right angles.

Front

What are parallel lines?

Back

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

Front

How many pairs of parallel sides does a trapezoid have?

Back

A trapezoid has at least one pair of parallel sides.

Front

What is an acute angle?

Back

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

Front

How many acute angles can a triangle have?

Back

A triangle can have one, two, or three acute angles.

Front

What is a right angle?

Back

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

Front

How many right angles can a trapezoid have?

Back

A trapezoid can have none, one, or two right angles.

Front

What is a quadrilateral?

Back

A quadrilateral is a four-sided polygon.