Geometry Terms

Front

parallel lines

Back

Lines that stay the same distance from each other forever and never intersect

Front

perpendicular lines

Back

Lines that cross at a point and form 90° angles

Front

vertices

Back

A point where two or more lines come together; also called a corner on a polygon

Front

Acute angle

Back

An angle that is less than 90°

Front

Obtuse angle

Back

An angle that is more than 90° and less than 180°

Front

Straight angle

Back

An angle that is exactly 180°

Front

Complementary angles

Back

Two angles that add up to 90°

Front

Supplementary angles

Back

Two angles that add up to 180°

Front

Opposite angles

Back

Angles that are across from each other; they do not share a side or vertex

Front

Adjacent angles

Back

Two angles that are formed with a common side