Geometry

10.3 Area of Parallelograms

Objectives:Find the areas of parallelograms.Find the areas of shaded region

Area of Parallelograms

A = bh h

b

JustificationYou can justify the

area formulas for parallelograms as follows.

The area of a parallelogram is the area of a rectangle with the same base and height.

Using the Area Find the area of ABCD.

Use AB as the base.

So, b=12 and h=9

Area=BH=12(9) = 108 square units.

12

16

E

A

C

D

B

9

EXAMPLE 1 Use a formula to find area

SOLUTION

Method 1

Method 2

Find the area of PQRS.

Use PQ as the base. Then the height is QT. So, b =12 and h = 4.

Area = bh

The base is extended to measure the height RU. So, b = 6 and h = 8.

Use PS as the base.

=12(4) = 48 square units

GUIDED PRACTICE for Example 1

2.

100 units, 510 units2

ANSWER

Find the perimeter and area of the polygon.