The document provides formulas and examples for calculating the perimeter and area of various geometric shapes, including: - Rectangle: Area = length x width, Perimeter = 2x length + 2x width - Triangle: Area = 1/2 x base x height - Irregular shape: Area is the sum of the individual areas of its parts. Perimeter is the total distance around the shape. - Parallelogram: Area = base x height - Trapezoid: Area = (base 1 + base 2) x height / 2 - Rhombus: Area = 1/2 x diagonal 1 x diagonal 2 It then provides examples of calculating areas for various shapes using these formulas.

1. Geometry Drill 4/22/14
 In your own words define
perimeter and area
 Make a list of any formula you
know that applies to perimeter or
area of a geometric figure.

2. Objective
SW recall area and
perimeter formulas so
that they can find the
area and perimeter of
irregular regions.

3. Compare:
Regular polygons vs.
polygons

4. Perimeter of a
Rectangle
P=2b+2h
h
b

5. Area of a Rectangle
A=bh
h
b

6. Area of a Triangle
A=(1/2)bh
h
b

7. Irregular Region
A region(shape)
composed of many
smaller
regions(shapes)

8. Area of an Irregular
Region
The sum of the areas
of all the non-
overlapping parts of
the region

9. Find the area of the
irregular region
43
2

10. Perimeter of an
Irregular Region
The distance
around the
region.

11. Find the Perimeter of
the region
43
2

12. Conclusions
 1) To find the area of an
irregular region, find the
areas of its smaller
_____ and find their
_____.

13. Conclusions
 1) To find the area of an
irregular region, find the
areas of its smaller
_____ and find their
_____.
parts
sum

14. Conclusions
 2) To find the perimeter
of an irregular region,
find the ________
around the region.

15. Conclusions
 2) To find the perimeter
of an irregular region,
find the ________
around the region.
distance

16. Find the perimeter of
rectangle ABCD
A
B
C
D
5 in.
3 in.
4 in.

17. EXPLORATION
We know how to find
the area of a rectangle.
How can I form a
rectangle from this
parallelogram?

18. Parallelogram

19. Parallelogram

20. Parallelogram

21. Parallelogram

22. Parallelogram

23. Parallelogram

24. Rectangle

25. b2
b2
b1
b1
h
h

26. b2
b2
b1
b1
h
h

27. b2
b1
h
b2
b1
h

28. b2
b1
h
b2
b1
h

29. b2
b1
h
Parallelogram
b1
b2

30. AREA OF A
PARALLELOGRAM
A = bh

31. AREA OF A
TRIANGLE
A = 1/2(bh)

32. AREA OF A
TRAPEZOID
A = h/2(b1+b2)
b1 and b2 are the
bases

33. ALTERNATE
FORMULA AREA
OF A TRAPEZOID
A = length of
median times the
height

34. Find the Area of
Trapezoid ABCD
12
10

35. ABCD is a rhombus with
diagonals d1 & d2
D C
A B

36. AREA OF A
RHOMBUS
A = 1/2(d1d2)
d1 and d2 are the
diagonals

37. Find the area:
10
5
6

38. Find the area:
5
42

39. Find the area:
5
12
8

40. Find the area:
12
9
15

41. Find the area:
8
57

42. Area of a
Rhombus
Find the area of a
rhombus if the lengths
of the diagonals are
12m and 10 m.