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

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

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

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.

Calculate the scale factor used to dilate the triangle. Quiz 2-14-11 Calculate the scale factor used to dilate the triangle. 5

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

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

Problem of the Week & Word Problem #4-4 1. 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

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

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

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

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

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

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.

Surface Area of Cylinders 3 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 = 188.4 units2

Surface Area of Cylinders 3 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) + 6.28 (9) TotalS = 188.4 + 56.52 TotalS = 244.92 units2

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 = 50.24 in2

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) + 6.28(4) TotalS = 50.24 + 25.12 TotalS = 75.36 in2

Surface Area of Cylinders 14 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 = 439.6 units2

Surface Area of Cylinders 14 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) + 6.28 (49) TotalS = 439.6 + 307.72 TotalS = 747.32 units2

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 = 200.96 in2

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 = 200.96 + 100.48 TotalS = 301.44 in2

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. 122 in3 40 in2 c. 40 in3 115 in2 d. 115 in3

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=56 + 24 + 42 = 122 in2

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

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

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

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

Incorrect Try Again! Review1

Incorrect Try Again! Review2

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

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