1. Exercise Simplify s + s + s + s. 4s4s4s4s

2. Simplify l + w + l + w. 2l + 2w Exercise

3. Solve 22 = 7p. p = 3 ≈ 3.14 1717 1717 Exercise

4. Solve 4s = 84. s = 21 Exercise

5. Solve 33 + 2w = 45. w = 6 Exercise

6. perimeter—distance around a plane geometric figure

7. Perimeter Formulas for Polygons Triangle aa bb cc p = a + b + c

8. Perimeter Formulas for Polygons Rectangle p = 2l + 2w ll ww

9. Perimeter Formulas for Polygons Square p = 4s ss

10. Perimeter Formulas for Polygons Parallelogram p = 2a + 2b aa bb

11. Perimeter Formulas for Polygons Trapezoid p = a + b + c + d aa cc bb dd

12. Find the perimeter of the polygon. 4 m 5 m 7 m p = 4 + 5 + 7 = 16 m Example 1

13. Find the perimeter of the polygon. 5 ft. 12 ft. p = 5 + 12 + 5 + 6 = 28 ft. 6 ft. Example 1

14. A parallelogram has a perimeter of 30 in. and a side of 6.5 in. Find the length of the other parallel sides. Example 2

15. 2a + 2b = p b = 8.5 2(6.5) + 2b = 30 13 + 2b = 30 13 + 2b – 13 = 30 – 13 2b = 17 2222

16. What is the perimeter of a square if the length of a side is 12? 48 Example

17. What is the length of a side of a square if its perimeter is 88? 22 Example

18. What is the length of a diagonal of a square if the length of a side is 12? 12 √ 2 ≈ 17 Example

19. What is the length of a side of a square if the length of a diagonal is 25.5? 18 Example

20. What is the perimeter of a regular decagon if the length of a side is 14.5? 145 Example

21. What is the length of a side of a regular decagon if its perimeter is 167? 16.7 Example

22. A circle is the set of points in a plane that are equidistant from a fixed point called the center. Circle

23. Chord A chord is a line segment with both endpoints on a circle. BC and AD are chords. BB AA CC DD EE OO

24. Diameter A diameter (d) is a chord passing through the center of a circle. The chord AD is a diameter of circle O. BB AA CC DD EE OO

25. Radius A radius is a line segment from the center of a circle to a point on the circle. BB AA CC DD EE OO OA, OD, and OE are radii of circle O.

26. circumference—distance around a circle

27. Circumference Formula for Circles c = πd c = 2πr The circumference is equal to π times the diameter. The circumference is equal to two times π times the radius.

28. Find the circumference of a circle with a radius of 5.3 cm. Round to the nearest tenth. = 33.3 cm c = 2πr = 2π(5.3) = 10.6π = 10.6(3.14) = 33.284 Example 3

29. Find the circumference of a circle with a diameter of 8 ft. Round to the nearest tenth. = 25.1 ft. c = πd = π(8) = 8π = 8(3.14) = 25.12 Example 3

30. Find the diameter and radius of a circle with a circumference of 30 in. Round to the nearest tenth of an inch. d ≈ 9.6 in. πd = c 3.14d = 30 3.14 r = d2d2 d2d2 = 4.8 in. Example 4

31. What is the circumference (to the nearest tenth) of a circle if its radius is 12? 75.4 Example

32. What is the circumference (to the nearest tenth) of a circle if its diameter is 20? 62.8 Example

33. What is the radius (to the nearest tenth) of a circle if its circumference is 112? 17.8 Example

34. What are the dimensions of a rectangle whose perimeter is 32 and whose longer side is three times the length of its shorter side? 4 by 12 Example

35. What are the dimensions of a triangle whose perimeter is 30 and whose sides are in the proportion 1 : 2 : 3? 5, 10, and 15 Example