1. 10.3 Area of Parallelograms
Geometry

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

3. Area of Parallelograms
A = bh h b

4. Justification
You 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.

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

6. EXAMPLE 1
Use a formula to find area
Find the area of PQRS.
SOLUTION
Method 1
The base is extended to measure the height RU. So, b = 6 and h = 8.
Use PS as the base.
Method 2
Use PQ as the base. Then the height is QT. So, b =12 and h = 4.
Area = bh
=12(4)
= 48 square units

7. GUIDED PRACTICE
for Example 1
Find the perimeter and area of the polygon. 2.
100 units, 510 units2
ANSWER