Vocabulary: Stretching & Shrinking Investigation 2.3 Scale Facrs Similar For 2 figures be similar, the following must be true: The corresponding side lengths of one figure are MULTIPLIED by the SAME number get the corresponding side lengths in the second figure. Corresponding angles are the same size. Scale Facr The NUMBER that the sides lengths of one figure can be MULTIPLIED by get the corresponding side lengths of the other figure. What is the scale facr Rectangle A Rectangle B below? What is the scale facr Rectangle B Rectangle A below?
Part A: The diagram below shows a collection of the mouths the Wump family and some imposters. Decide which rectangles are similar and fill in the blanks. Rectangles and are similar. The scale facr Rectangle is. The perimeter of Rectangle is & the perimeter of Rectangle is. What would you multiply Rectangle s perimeter by get Rectangle s perimeter? The area of Rectangle is & the area of Rectangle is. What would you multiply Rectangle s area by get Rectangle s area?
Rectangles and are similar. The scale facr Rectangle is. The perimeter of Rectangle is & the perimeter of Rectangle is. What would you multiply Rectangle s perimeter by get Rectangle s perimeter? The area of Rectangle is & the area of Rectangle is. What would you multiply Rectangle s area by get Rectangle s area? Rectangles and are similar. The scale facr Rectangle is. The perimeter of Rectangle is & the perimeter of Rectangle is. What would you multiply Rectangle s perimeter by get Rectangle s perimeter? The area of Rectangle is & the area of Rectangle is. What would you multiply Rectangle s area by get Rectangle s area?
Part B: The diagram below shows a collection of the noses the Wump family and some imposters. Decide which triangles are similar and fill in the blanks. Triangles and are similar. The scale facr Triangle is. HINT: when you calculate the area of a triangle, count the boxes the base of the triangle straight up the highest point of the triangle. The area of Triangle is & the area of Triangle is. What would you multiply Triangle s area by get Triangle s area?
Triangles and are similar. The scale facr Triangle is. The area of Triangle is & the area of Triangle is. What would you multiply Triangle s area by get Triangle s area? Triangles and are similar. The scale facr Triangle is. The area of Triangle is & the area of Triangle is. What would you multiply Triangle s area by get Triangle s area? Part C: Use your responses parts A and B complete the SUMMARY OF YOUR FINDINGS TABLES on the next page & then answer the questions that follow.
Summary of Your Findings: Complete the tables below with the data parts A & B of the investigation. (original) (new) (original new) Rectangle Rectangle Scale Facr What would you multiply the original perimeter by get the new perimeter? What would you multiply the original area by get the new area? (original) (new) (original new) Triangle Triangle Scale Facr What would you multiply the original area by get the new area?
1) Describe the relationship between the perimeters of two similar figures and the scale facr. 2) Describe the relationship between the areas of two similar figures and the scale facr. Part D: After studying the mouths in the diagram, Marta and Zack agree that rectangles J and L are similar. Marta says the scale facr is 2. Zack says the scale facr is 0.5. 1) Is either of them correct? How would you describe the scale facr so that there is no confusion? 2) Explain how find the scale facr a figure a similar figure. 3) Does scale facr change the angle size? Explain.