Geometry Vocabulary
1. Geometry-the study of shapes
2. Polygon-a flat shape (2 dimensional shape) with a least three sides and one angle
3. Polyhedron-(plural polyhedra or polyhedrons) is a geometric solid in three dimensions with flat
faces and straight edges.
4. Congruent-same size, same shape
5. Line of symmetry-a line that dissects a figure/shape into mirrored parts (identical parts on both
sides of the symmetry line)
6. Vertex or point-a dot forming an angle that may also create a shape. The plural form is vertices.
7. Line segment-a line with a beginning vertex and an ending vertex. This is called an edge when a
line segments combine to form a shape.
8. Line-a never ending line with a beginning arrow and an ending arrow
9. Angle-where two lines meet at a vertex
10. Ray-a line beginning with a vertex and ending with an arrow like a one way street
Polygons-2 d Polyhedrons-3 d Circular shapesshapes
shapes
2d and 3d
These shapes may be
identified by vertices, sides,
and angles.
These shapes may be
identified by vertices, edges,
and faces.
These shapes may be identified
by their vertices, circular
patterns, or bases.
Triangle-three sided shape
Pyramid-a 3d shape with
vertices, edges, and faces.
The base will determine the
type of pyramid. A pyramid
will have one vertex at the top
tip of the shape. Types of
pyramids include: triangular
pyramids, square pyramids,
and rectangular pyramids,
etc.
Circle-a round 2d shape
Oval-a curved shape that is
stretched wider on two sides.
Quadrilateral-four sided
shape (This includes
squares, rectangles,
trapezoids,
rhombus/rhombi, and
parallelograms)
Pentagon-five sided shape
Hexagon-six sided shape
Heptagon-seven sided shape
Octagon-eight sided shape
Nonagon-nine sided shape
Sphere-a round 3d shape
Ellipse-a curved 3d shaped that
is stretched wider on two sides.
Cone- solid figure generated
by the straight lines that pass
from a circle or other closed
curve to a single point (the
vertex).
Prism- a 3d shape with
vertices, edges, and faces.
The bottom face will
determine the type of prism. 1.
Cylinde
Types of prisms include:
r- A solid geometric figure
cubes, rectangular prisms,
with straight parallel sides
and triangular prisms, etc.
and a circular or oval
section.
Decagon-ten sided shape