Unit 7 Lesson 2 Similar Polygons
Unit 7 Lesson 2: Similar Polygons
Lesson Overview
Similar Polygons
What You Will Learn
- similar figures have the same shape but not necessarily the same size
Overview
In this lesson, you will learn that similar figures have the same shape but not the same size. You can abbreviate 'is similar to' with the symbol ~.
Essential Understanding
You can use ratios and proportions to decide whether two polygons are similar and to find unknown side lengths of similar figures.
- Read Pages 264-271 in your course textbook.
This course is based on a textbook that is viewable by clicking on the textbook icon. Keep the textbook open while you go through the lesson so that you may refer to it throughout the lesson.
Lesson 2: Similar Polygons
Resource Videos
Similar Polygons Part 1
Similar Polygons Part 2
Proceed to the Next Page
Prepare for Application
Instructions
For questions 1 and 2, DEFG ~HJKL.
- What are the pairs of congruent angles?
- What is the extended proportion for the ratios of the lengths of corresponding sides?
Are the polygons similar? If they are, write a similarity statement and give the scale factor.
Are the polygons similar? If they are, write a similarity statement and give the scale factor.
In the diagram below, what is the value of y?
Your class is making a rectangular poster for a rally. The poster's design is six in. high by ten in. wide. The space allowed for the poster is 3 ft high by 4 ft wide. What are the dimensions of the giant complete poster that will fit in this space?
- Refer to the scale drawing in Problem 5 on page 443 of your textbook. What is the actual height of the towers above the roadway if the height in the scale drawing is 0.8 cm?
- The Space Needle in Seattle is 605 ft tall. A classmate wants to make a scale drawing of the Space Needle on an in.-by-. Sheet of paper. He decides to use the scale 1 in. = 50 ft. Is this a reasonable scale? Explain.