Unit 6 “Area and Volume” Vocabulary Vocabulary
Word
Definition
Picture
2-dimensional (2D)
shapes
Shapes that only have 2
dimensions
Perimeter
The distance around a figure,
measured in units such as
feet, inches, or meters
Area
The amount of surface
covered by a figure;
measured in square units.
Triangle
A closed plane figure with 3
straight sides that connect
three points.
Parallelogram
A quadrilateral with two
pairs of parallel sides
Base
The length of any of a
figure’s sides (typically found
along the bottom edge).
Height
Circle
Center
The perpendicular distance
between the side whose
length is the base and the
opposite side.
The set of all points in a
plane that are the same
distance from a point called
the center.
The point inside a circle that
is the same distance from all
points on the circle.
Diameter
The distance across the
circle through its center.
Radius
The distance from the
center of a circle to any
point on the circle.
Pi
The ratio of the
circumference of a circle to
its diameter ( ! )
3-dimensional (3D)
shapes
Shapes that have 3
dimensions
Faces
The polygons that form the solid figure. Edges
The segments where the faces meet. Vertex (pl.
vertices)
The endpoint of the rays that form the angle. Volume
The amount of space that a 3-­‐D object occupies; measured in cubic units. Surface area
The sum of the areas of the
faces on a 3-D shape;
measured in square units.
Prisms (rectangular
and triangular)
A solid with two parallel
bases (either rectangular or
triangular) that are
congruent polygons.
Pyramids
(rectangular and
triangular)
A solid made up of polygons.
The base is usually either a
triangle or a quadrilateral.
Cones
A solid that has one circular
base and a vertex that is not
in the same plane.
Cubes
A rectangular prism with 6
congruent faces.
Cylinders
A solid with two parallel
bases that are congruent
circles.
spheres
The set of points in space
that are a given distance
from a given point
Fill in any other area/volume-related words you come across below.