Geometry Vocabulary

Front

A flat or curved surface of a solid.

Back

face

Front

A three-dimensional figure that encloses a space.

Back

solid

Front

A point where three or more edges of a polyhedron intersect.

Back

vertex

Front

A line segment or curve where two faces of a solid intersect.

Back

edge

Front

A solid whose faces are all polygons.

Back

polyhedron

Front

A closed figure in a plane that is made up of three or more line segments that intersect only at their endpoints: for example, parallelograms and triangles.

Back

polygon

Front

A figure with 4 straight sides.

Back

quadrilateral

Front

Lines that intersect at a right angle, 90°.

Back

perpendicular lines

Front

Two lines on the same plane; never intersect; always the same distance apart.

Back

parallel lines

Front

Flat, two-dimensional object.

Back

plane