(-) + (-) = ? (+) x (+)= ? (-)+(+)= ? 12.07.2017 Ticket in the Door Agenda Ticket in the Door Ticket in the Door Review of Ticket in the Door Current lesson: Wrap-up (-) + (-) = ? (+) x (+)= ? (-)+(+)= ?

scale factor

Scale factor is the ratio of change between two sides. The number you multiply by to relate the first shape to the second is the scale factor.

Understanding Scales All scale drawings must have a scale written on them. Scales are usually expressed as ratios. Normally for maps and buildings the ratio: Drawing length: Actual length For maps the ratio is normally in the ratio: Map distance: Actual Distance Example: 1cm : 100cm The ratio 1cm:100cm means that for every 1cm on the scale drawing the length will be 100cm in real life Example: 1:10000 The ratio 1:10000 means that the real distance is 10000 times the length of one unit on the map or drawing.

If you have ever seen Jurassic Park, you saw how big the dinosaurs were compared to the people. Pretend that they made a large Human to watch over the animals. What would be the scale factor if a 64 inch person was made to be 160 feet?

The scale factor tells you how many times bigger than “normal” that person really is. You must make all units of measure the same…. 64 inches 64 inches 64 inches = = 160 feet 1920 inches 160 x 12

Now take the: 64 inches And simplify 1920 inches 1/30 inches This means that the person was created 30 times his normal size.

If a shape becomes twice as big, the scale factor would be two. If a shape shrinks to half its size, the scale factor is ½. Let’s take a look.

Take a look at the RED shape, Now Look at the BLUE

How many times bigger is the blue shape? 10 2 is your scale factor because 5 x 2 = 10 and 4 x 2 = 8 5 4 What did you get? 8

transformation, what has been the amount of reduction? Both 6 and 9 reduce in size by dividing 3 BUT scale factor must be a relation by multiplying. 6 For 6 to become 2, you must multiply by 1/3 and for 9 to become 3 you must also multiply by 1/3. So your scale factor is….1/3 9 2 3 Now take a look at the transformation, what has been the amount of reduction?

Both 2 and 3 are multiplied by 4. This means the scale factor is 4. 8 12 Both 2 and 3 are multiplied by 4. This means the scale factor is 4. Now take a look at the transformation, what has been the amount of enlargement?

What is the scale factor? 5 15 7 21 A B C D 3 1/3 5 10

What is the scale factor? 8 16 B A C D 3 2 1/2 8

What is the scale factor? 4 12 A B C D 3 1/2 1/3 9

What is the scale factor? 3 18 A B C D 9 4 1/6 6

A Mustang GT is 16 feet long. A model of it was built with a scale of 1 in : 2 ft. How long is the model. A B C D 9 in 16 in 16 ft 8 in