RY
Third Grade Geometry Vocabulary
1. angle - A figure formed by two rays or line segments that share an endpoint.
right angle A special
angle that
forms a
square corner
obtuse angle - An angle
that has a measure
greater than a right angle
acute angle An
angle that has a
measure less than
a right angle
GLOSSARY
congruent - Figures that have the same size and shape.
Polygon
A closed shape formed by five o
Sometimes
quadrilaterals
and tr
parallel lines - Lines that never cross; lines that are always
the same distance
apart.
be a polygons.
Example:
GLOSSARY
Appendix A
two dimensional shape – a plane (flat) figure that has 2 dimensions, length and width
polygon - A closed plane (flat) figure with straight sides that are line segments.
Polygon
A closed shape formed by five or more line seg
ape formed
by five or more line segments.
Sometimestoquadrilaterals
triangles are
con
opened
pentagonand
quadrilaterals and triangles are
considered
hexag
curved
not
a
polygon
(5 sides)
ns.
be a polygons.
not a polygon
(6 side
hexagon
(6 sides)
heptagon
pentagon
(7 sides)
(5 sides)
octagonhexagon
(8 sides)(6 sides)
nonag
(9 sid
three dimensional shape – a solid figure that has three dimensions, length, width, and
height
nonagon
(9 sides)
Polyhedron
(pl. Polyhedra)
Solid shapes which have surface
and polygons.
Pre-image
decagon
(10 sides)
octagon
A point or shape before it has un
(See image for illustration)
Prism
nonagon
A solid that has two parallel poly