Quadrilaterals
10-9
BCAD
MNOP
MONP
STUV
SUTV
EFGH
EGFH
JKLR
JLKR
Quadrilaterals are four-sided polygons. They can be classified
according to the special properties of their sides or angles.
A trapezoid is a quadrilateral with
exactly one pair of parallel sides.
A parallelogram is a quadrilateral with
two pairs of parallel congruent sides.
Opposite sides as well as opposite
angles are congruent.
A rectangle is a parallelogram
with four right angles.
A square is a parallelogram with four
right angles and four congruent sides.
A rhombus is a parallelogram with
four congruent sides.
The diagram below shows how the different types of quadrilaterals are related.
rectangle
parallelogram
quadrilateral
square
rhombus
trapezoid
B C
A D
M N
O P
S T
U V
E
J
L
K
R
G
F
H
8206-2_346-347 10/12/07 6:49 PM Page 346