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Workbook p.217 Activity 4 2 4 4=22

Workbook p.218 #6 Ratio of heights: 1.5 Ratio of perimeters: 1.5 Ratio of Areas: 2.25 Ratio of heights: 1.67 Ratio of perimeters: 1.67 Ratio of Areas: 2.78

Workbook p.218 #7 #8 k= 3 0.8 Perimeter of initial: 10cm #7 #8 k= 3 0.8 Perimeter of initial: 10cm Perimeter of image: 30cm #9 Area of initial: 5.1cm2 k2=2.25 so k=1.5 Area of image: 45.9cm2 Per. of small:20cm Per. of large:30cm #10 Big area: 600  cost per m2: 12$ Small rectangle’s dimensions: 15 by 10 small area: 150 Cost of small: 150x12=1800

Ratio of Volumes

How to find the Volume of the image Scale Factor: k3 Volume of the initial x k3 = volume of the image

Example 1 Find the volume of the image. Step 1 – Find k k = 6 = 2 3 V=???cm3 Initial V=60cm3 3 4 6 5 Step 1 – Find k k = 6 = 2 3 Step 2 – Find the volume of the initial v=5x4x3 = 60cm3 Step 3 – Find the volume of the image 60x23 = 480cm3

Example 2 Find the radius of the image. Step 1 – Find k3 V=8181.23 V=26521.86 Step 1 – Find k3 k3 = 26521.86 = 3.24 8181.23 Step 2 – Find k k=³√3.24 = 1.47 Step 3 – Find the radius of the image 12.5 x 1.47 = 18.47

Things to Remember about Similarity k is the ratio of sides(and perimeter) k2 is the ratio of area k3 is the ratio of volume

To get from one ratio to another Ratio of volume to ratio of sides  k3 to k ³√ k3 = k Ratio of volume to ratio of areas  k3 to k2 ³√ k3 = k then square it to get k2 Ratio of areas to ratio of volumes  k2 to k3 √ k2 = k then cube it to get k3

Homework - START NOW  Workbook p. 222 # 5 to 9 p. 223 all