Head First 2D Geometry

parallelograms

The lawn is a parallelogram

It kinda looks like a rectangle, but squished down so the sides are

slanted. A parallelogram is a four-sided shape whose opposite

sides are parallel to each other.

A rectangle:

Rectangles have two pairs of

parallel sides. The parallel sides are

also congruent.

Each of the four corners forms a

right angle.

A parallelogram:

Parallelograms have two pairs of

parallel sides, too, and like a rectangle,

the parallel sides are also congruent.

Unlike a rectangle, the corners of a

parallelogram aren’t right angles. The

most we can say is that opposite corner

angles are congruent.

So what should you charge?

We need to calculate the charge for mowing a lawn in the shape

of a parallelogram, and to do this, we need to work out the area.

You know how to do that for a rectangle, but would that work for a

parallelogram, too?

A parallelogram is

a four-sided shape

whose opposite

sides are parallel.

238 Chapter 6