1. Bell Ringer 2-14-11 Figure A is dilated to create Figure B. A B
What type of dilation occurred?
Calculate the scale factor.
Calculate the original volume.
Calculate the new volume.
How is the volume affected?
3 in
2 in
1 in
1.5 in
4 in
6 in 1

2. Figure A is dilated to create Figure B. A B
What type of dilation occurred?
Calculate the scale factor.
3 in
2 in
1 in
1.5 in
4 in
6 in
Enlargement

3. Figure A is dilated to create Figure B. A B
Calculate the original volume.
4. Calculate the new volume.
3 in
2 in
1 in
1.5 in
4 in
6 in

4. Figure A is dilated to create Figure B.
A B
5. How is the volume affected?
3 in
2 in
1 in
1.5 in
4 in
6 in
Say NO to Oreos!
The new volume is 3 3/8 times larger than the original volume.

5. Calculate the scale factor used to dilate the triangle.
Quiz
Calculate the scale factor used to dilate the triangle. 5

6. What is the scale factor?
Calculate the scale factor used to dilate the triangle.
Triangle ABC
Enlargement
AB= 14 cm
BC= 12 cm
A’C’= 21 cm
B’C’= 18 cm
What is the scale factor?
To find the scale factor, I divided the new dimension by the original dimension. Since, the new dimensions are larger, an enlargement occurred. Since it is an enlargement, the scale factor should be greater than 1.
The scale factor is 1.5. 6

7. Speed Test 1. Get out a dry erase marker.
2. You have 1 minute to complete as many problems as you can.
We will grade in 1 minute.
4. Graph your results. Keep the graph in your notebook.
5. We will do this every day. 7

8. Problem of the Week & Word Problem
# You have 5 minutes to work on the problem of the week and word problem. 2. The problem of the week must follow the Read, Think, Solve, Justify format. 3. When you are finished, turn them in. 4. They are due Friday. 8

9. Reach for the Stars Monday
Rebecca earns a salary of $200 per week plus an additional 5% commission on her sales. If Rebecca’s weekly salary increases by $25 and her commission increases to 6%, how much will she earn if her weekly sales are $2,500?
$325.00
$375.00
$525.00
$700.00

10. Class Work: Surface Area of Cylinders
You need your notes. Title the notes: Surface Area of Cylinders I will check your work at the end of class. 10

11. the sum of the areas of the exposed surfaces
Surface Area
the sum of the areas of the exposed surfaces
Perimeter is measured in
Units
Area is measured in
Square units = units2
Volume is measured in
Cubic Units = units3 11

12. Surface Area of Cylinders
Lateral: S = 2πrh
Curved face only
Total: S = 2πrh+2πr2
Curved face and 2 end circles

13. Surface Area of Cylinders
Cylinder Net
2πrh: “rectangle part”
  Curved Face
2πr2: circles

14. Surface Area of Cylinders
Determine what we are looking for
Write down the formula.
Identify the radius.
Identify the height.
Plug r and h into the formula.
Solve.

15. Surface Area of Cylinders3
Calculate the lateral and total surface area of the figure.
r = 3
h = 10 10
LateralS = 2πrh
LateralS = 2(3.14)(3)(10)
LateralS = 6.28 (30)
LateralS = units2

16. Surface Area of Cylinders3
Calculate the lateral and total surface area of the figure. 10
r = 3
h = 10
TotalS = 2πrh+2πr2
TotalS = 2(3.14)(3)(10) + 2(3.14)(32)
TotalS = 6.28 (30) (9)
TotalS =
TotalS = units2

17. Surface Area of Cylinders
Calculate the lateral and total surface area of the figure.
2 in
r = 2 in
h = 4 in
4 in
LateralS = 2πrh
LateralS = 2(3.14)(2)(4)
LateralS = 6.28(8)
LateralS = in2

18. Surface Area of Cylinders
Calculate the lateral and total surface area of the figure.
2 in
r = 2 in
h = 4 in
4 in
TotalS = 2πrh+2πr2
TotalS = 2(3.14)(2)(4)+2(3.14)(22)
TotalS = 6.28 (8) (4)
TotalS =
TotalS = in2

19. Surface Area of Cylinders14
Calculate the lateral and total surface area of the figure. 10
r = 7
h = 10
LateralS = 2πrh
LateralS = 2(3.14)(7)(10)
LateralS = 6.28 (70)
LateralS = units2

20. Surface Area of Cylinders14
Calculate the lateral and total surface area of the figure. 10
r = 7
h = 10
TotalS = 2πrh+2πr2
TotalS = 2(3.14)(7)(10) + 2(3.14)(72)
TotalS = 6.28 (70) (49)
TotalS =
TotalS = units2

21. Surface Area of Cylinders
A roll of paper towels has a radius of 4 in and a height of 8 in. How much paper is needed to wrap around the roll?
r = 4 in
h = 8 in
LateralS = 2πrh
LateralS = 2(3.14)(4)(8)
LateralS = 6.28 (32)
LateralS = in2

22. Surface Area of Cylinders
A roll of paper towels has a radius of 4 in and a height of 8 in. How much plastic is needed to cover the roll?
r = 4 in
h = 8 in
TotalS = 2πrh+2πr2
TotalS = 2(3.14)(4)(8)+2(3.14)(42)
TotalS = 6.28 (32)+6.28(16)
TotalS =
TotalS = in2

23. Review Questions
A rectangular box with length of 4 inches, height of 7 inches, and width of 3 inches is being used to wrap a present. How much wrapping paper is needed to cover the box? How many cubic inches can the box hold?
84 in2 a. 84 in3
122 in2 b in3
40 in2 c. 40 in3
115 in2 d in3

24. Front and Back: A=4(7)= 28 in2 Top and Bottom: A=4(3)=12 in2
A rectangular box with length of 4 inches, height of 7 inches, and width of 3 inches is being used to wrap a present. How much wrapping paper is needed to cover the box? How many cubic inches can the box hold?
Front and Back: A=4(7)= 28 in2
Top and Bottom: A=4(3)=12 in2
Right and Left side: A=3(7)=21 in2
TotalS=2(28) + 2(12) + 2(21)
TotalS= = 122 in2

25. V = lwh V = (4)(3)(7) V = (12)(7) V = 84 in3
A rectangular box with length of 4 inches, height of 7 inches, and width of 3 inches is being used to wrap a present. How much wrapping paper is needed to cover the box? How many cubic inches can the box hold?
V = lwh
V = (4)(3)(7)
V = (12)(7)
V = 84 in3

26. Volume Review #1
The volume of a rectangular prism is 210 m3. If the length is 5 meters and the height is 7 meters, how wide is the prism?
A. 8 meters
B. 6 meters
C. 5 meters
D. 7 meters

27. Volume Review #2 A. 3 in B. 81 in C. 15 in D. 9 in
A square pyramid has a volume of 27 in3. If the base of the pyramid has an area of 9 in2, what is the height of the pyramid?
A. 3 in
B. 81 in
C. 15 in
D. 9 in

28. Class Work
Measuring Up pg. 186: all Find the lateral and total surface area

29. Incorrect
Try Again!
Review1

30. Incorrect
Try Again!
Review2

31. Correct
Way To Go!
210 =(5)(7)(w)
210 = 35w
210 = 35w 35
review1
6 = w

32. Correct
Way To Go!
27 = ⅓(9) (h)
27 = ⅓ (9h)
27 = 3h 3
Review2
9 = h