This document provides information on calculating the perimeter of polygons and the circumference of circles. It defines various polygons and explains that to find the perimeter of a polygon you sum the lengths of all its sides. The document also defines key terms related to circles like diameter and radius, and provides the formulas to calculate circumference as either π times the diameter or 2π times the radius.

3. 1. gain knowledge about the perimeter
2. Recognize the formulas for perimeter
and circumference

4. 3. find the perimeter of polygons
4. find the circumference of circle

6. It is the
of a .

7. Polygon

8. A is a closed figure whose sides
are .
A is a polygon having all
sides congruent and all angles congruent.

9. Triangle (3)
Square (4)
Pentagon (5)
Hexagon (6)
Heptagon (7)
Octagon (8)
Nonagon (9)
Decagon (10)
Hendecagon (11)
Dodecagon (12)
Tridecagon (13)
Tetradecagon (14)
Pendedecagon (15)
Hexdecagon (16)
Heptdecagon (17)
Octdecagon (18)
Enneadecagon (19)
Icosagon (20)

11. To find the perimeter of a polygon:
1. just get the sum of all the lengths
of the sides of that polygon.

12. Example 1:
5 cm
9 cm
7 cm
𝑃 = 5 +7 + 9
𝑃 = 21 𝑐𝑚.

13. Example 2:
12 m
14 m
𝑃 = 12+14
𝑃 = 26 𝑚.

14. Example 3:
11.5 cm.
𝑃 = 11.5 (8)
𝑃 = 92 𝑐𝑚.
11.5 cm.
11.5 cm.
11.5 cm.
11.5 cm.
11.5 cm.
11.5 cm.
11.5 cm.

16. A is a
in a plane that
are at the same
distance form a given
point in the plane.
Thus, called the
.
center

17. A is a
in a plane that
are at the same
distance form a given
point in the plane.
Thus, called the
.
center

18. In the circle on the left:
-Point C is in the interior of the circle.
-Point E is in the exterior of the circle.
-Points A, D, and B lie on the circle
-Center: point O
-Radius: OA, OB, OD
-radius is one-half the diameter
-Diameter: AB
-a diameter is twice the radius.
A
C
O
D
EB

19. The of
a circle is the
.
center

20. Formula:
𝐶 = 𝜋𝑑 𝑜𝑟 2𝜋𝑟
where d is the
and r is the .

22. Formula:
𝐶 = 𝜋𝑑 𝑜𝑟 2𝜋𝑟
where d is the
and r is the .
50 ft.
𝐶 ≈ 𝜋𝑑
𝐶 ≈ 3.14(50)
𝐶 ≈ 𝑓𝑡.
Example 1:
157

23. Formula:
𝐶 = 𝜋𝑑 𝑜𝑟 2𝜋𝑟
where d is the
and r is the .
14 cm.
𝐶 ≈ 2𝜋𝑟
𝐶 ≈ 2 (3.14)
𝐶 ≈ 𝑐m
Example 1:
(14)
87.92

24. question
s?