# Ratios and Proportions: Solving Problems with Similar Triangles

### Students will learn how to use proportions to solve problems involving similar triangles.

### Objectives:

• Students will learn how to use proportions to solve shadow problems.

• Students will learn the characteristics of similar triangles.

• Students will learn how to solve for the lengths of the sides of similar triangles using proportions.

• Students will practice solving these types of problems.

### Suggested Grades:

Sixth Grade - Seventh Grade - Eighth Grade - Ninth Grade - including special education students

Print the classroom lesson plan and worksheet questions (see below).

### Lesson Excerpt:

- "In our work with proportions, we have been working on several different things. We started out writing ratios. We learned that ratios are ways of comparing different things. Sometimes ratios compare quantities, sometimes shapes, but the important thing to remember is that we are comparing."

- "Then we started working on proportion. A proportion is formed when two ratios are equal. We have been identifying proportions and solving them too. Today, we are going to take all that we have learned about proportions and apply it to problem solving with similar triangles."

- "Let's review a few vocabulary words to help us in this process."

Continued...