
272 Chapter 6
your geometry toolbox
Quadrilateral
A flat shape with four
straight sides.
Your Geometry Toolbox
You’ve got Chapter 6 under
your belt and now you’ve added
quadrilaterals to your toolbox. For a
complete list of tool tips in the book, head
over to www.headfirstlabs.com/geometry.
CHAPTER 6
Parallelogram
Has two pairs of parallel sides
that are also congruent.
Opposite corner angles are
congruent.
Area = height x base width.
Rectangle
Has two pairs of parallel
congruent sides.
Every corner is a right
angle.
Area = width x height.
Trapezoid
Has one pair of parallel sides called bases.
Area = 1/2 x height x (base 1 + base 2)
Rhombus
Has four congruent sides.
Is both a parallelogram and
a kite—so you can use the
area calculation of either
shape.
Kite
Has two pairs of separate adjacent
congruent sides.
Diagonals are perpendicular.
Area = 1/2 x diagonal 1 x diagonal 2