Take out your homework and math journals Check your homework and record effort on your half sheet. Be ready to start class at 11:08 – with your math journals out! December 3, 2015 Warm-Up:Warm-Up:

Homework Karen’s New Problem

Objective SWBAT identify corresponding parts of similar figures, compare ratios of corresponding parts of similar figures, and relate the ratios to scale factor. Write down the objective in your math journal in your own words.

Corresponding Parts In Studying similar figures, we need to compare their sides and angles. In order to compare the right parts, we use the terms corresponding sides and corresponding angles. Each side in one figure has a corresponding side in the other figure. Also, each angle has a corresponding angle.

Corresponding Parts Consider the triangles below:

Scale Factor Think of a copy machine and what it does to a picture when the “enlargement” button is selected. Which of the following could be a photo copied image of the one on the left below?

The photo copier makes every length of the picture larger or smaller by multiplying it by the same number, called the multiplier. That multiplier is also called the scale factor. Scale Factor