1. Finding the Area of Rectangles and Parallelograms
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2. Warm Up Find the perimeter of each polygon. 1. 2. 3. 4. 156m 104m 9m

3. Finding the Area of Rectangles and Parallelograms

4. Area of a Rectangle Formula

5. Area of a rectangle = length x width

6. Ex. 1: Find the area of the rectangle.
A = l x w
A = 19cm x 12cm
12cm
A = 228cm2
19cm

7. Ex. 2: Find the area of the rectangle.
A = l x w
A = 8cm x 2cm
2cm
8cm
A = 16cm2

8. Another way to write the formula is Area = side x side or A = s2 .
A square is a rectangle so to the find the area of a square use the rectangle formula.
Since all sides of a square are congruent the area is found by finding 4 x 4.
4cm
Another way to write the formula is
Area = side x side or A = s2 .
A = 16cm2

9. Ex. 3: Find the area of the square.
A = s2
A =142
14 cm
A = 196cm2

10. Practice Find the area. 1. 2. 126in2 36m2 4. 3. 27cm 34cm 225m2 918cm2
126in2 6m
9in
36m2
14in 4. 3.
27cm
15m
34cm
918cm2
225m2

11. Area of a Parallelogram Formula

12. Area of a parallelogram Area = base x height
The base and height of a parallelogram must be perpendicular.

13. A = base x height A = 13m x 8m A =104m2
Ex.4: Find the area of the parallelogram. 8m
13m
A = base x height
A = 13m x 8m
A =104m2

14. Ex. 5: Find the area. 8
2x + 3
A = 8(2x + 3) = 16x + 24

15. Practice Find the area of the parallelograms. 1. 2. 7cm 3cm 14cm 6cm

16. Closure If the area of the parallelogram is 150ft2, what is the base?