Warm Up I will give 20 minutes to finish homework and ask questions Homework time A For problems 1 and 2 make sure you set up the equation or number sentence your are using For question 5 a and b you are looking for the scale factor, c is the area and d also relates to the scale factor For question 6 it is just multiple choice B For Q20 state scale factor you are multiplying by For Q21 Show how you are getting percent For Q23 a description is key, b description, c you can skip For Q24 a explanation, b you do not have to do

Homework Investigation 2 Worksheet on dilations Worksheet on scale factors A page 38 5,6,8 B page 44 31 and 32 Due Oct 4th Quiz Oct 5th

Stretching and Shrinking Students will be able to use scale factor to determine distances, students will be able to find unknown heights using similar figures.

Investigation 2: Similar Figures Students will continue to develop the definition of similar and determine rules and properties of enlarged and shrunken figures.

2.1 Drawing Wumps Essential Question: How can you determine if two shapes are similar by looking at the rule producing specific coordinates for the image?

Warm-Up If I enlarge an image by 300% (or multiple of 3) how does this affect the side lengths? Perimeter? Area? Solve the following

Homework Converting between feet and inches 5.6 feet is not 5 feet 6 inches Label Answers Make sure you answer question being asked

Problem 2.1 page 28 – When done with quiz finish pg 28 Play Video Get one Labsheet and graph paper per group Plot points for A to draw original figure For B fill in the table and plot points What does it mean when asked to do (2x,2y) Multiple the x by 2 and the y by 2 to get new coordinates Part C Compare – what do you notice Rules about similar figures? If x and y are multiplied by the same thing they will be similar

Warm-Up New Seats Calculate the perimeter and area of the parallelogram What is 5% sales tax on a $14.00 cd? What is the 15% tip on a $25.50 dinner at a restaurant?

Quiz Directions How did you get the number of books should be within ½ of actual, did you label and show how you calculated the value Naming the rectangle not if correct order, definition of corresponding Warm-up before quiz, question 2 on blue sheet, describe and calculate Dimension increased by a scale factor Expanded or factored form, never said solve

Finish Notes from Last Week Blue Sheet Question 3 Part C Compare – what do you notice How can you determine if two shapes are similar by looking at the rule producing specific coordinates for the image? If x and y are multiplied by the same thing they will be similar

2.2 Hats off to the Wumps Essential Question: What types of coordinate rules produce similar figures? NonSimilar Figures? For a pair of similar figures, how can you use a coordinate rule to predict the side lengths of the image?

Problem 2.2 page 31 You will get 1 lab sheet and 4 extra graphs to do this section Everyone help to get coordinates of Mugs Hat Divide up the remaining hats – get the coordinates, plot the new hat Do problems A – D What did you notice? What types of coordinate rules produce similar figures? Addition and Subtraction of either x,y or both coordinates Multiplication if done to both coordinates NonSimilar Figures? Multiplication if done only to one coordinate Not the same number multiplied to each coordinate For a pair of similar figures, how can you use a coordinate rule to predict the side lengths of the image? If both coordinates are multiplied by the same number, that is the scale factor

2.3 Mouthing off and Nosing Around Essential Question: How can you decide whether or not two shapes are similar?

Similar Play Video Same shape different size All the angles will be the same or congruent if shapes are similar All sides are proportional – meaning that all sides are multiplied by the same thing, scale factor Scale factor – number you are multiplying each side by, or each coordinate

Warm Up Have Investigation 2.3 notes out to be check 1. Is the following statement True or False, how could you determine it without doing the problem 2. Write Always, sometimes or never ( be able to support your answer) If m and n are positive rational numbers, then m+n is positive If m and n are negative rational numbers then m-n is negative If m is a positive rational number and n is a negative rational number, then m+n is negative 5−|−2|+|3|=5−|−2+3|

Homework Due Thursday Worksheet Side 1 – enlarging or shrinking a figure Write original order pairs, apply scale factor, plot new ordered pairs Side 2 – determine scale factor, show how, determine missing sides show how, setup Bookwork A 6 make sure you explain 8 show how you are figuring out rule c and d make sure you explain about Perim and Area B Writing rules 31 – how did you get the rule 32 Write down rules for zug and lug, how did you figure out rule

Problem 2.3 page 34 Do problems A, B, and C What did you notice How can you decide if two shapes are similar? When given two shapes look for all angles to be congruent Look for all pairs of corresponding sides to be the same scale factor

Key Ideas Looking at rules can you determine what is going to happen and if it would be similar Looking at the figures can you determine the rule to go from one to the other How Shifting L,R,U,D Stretching and Shrinking

More Examples What do the ordered pairs tell you? Which ones are similar?

Examples

Example Pg 44 number 30 Pg 45 number 34

Essential Questions How can you determine if two shapes are similar by looking at the rule producing specific coordinates for the image? What types of coordinate rules produce similar figures? NonSimilar figures? For a pair of similar figures, how can you use a coordinate rule to predict the side lengths of the image? How can you decide whether or not two shapes are similar?