# Finishing Up the Similar Triangles Project

## Objective

SWBAT to plan and write essays about the role that the Mathematical Practices have played in their exploration of similarity, the properties of right triangles, and the trigonometric ratios.

#### Big Idea

It's time for students to synthesize what they've learned about the trigonometric ratios, precision, similarity, and patterns. Today's work period gives students a chance to clarify their thinking and to put it in writing.

10 minutes

## How can you know if your theoretical values are accurate?

10 minutes

To review the big idea of the Similar Triangles Project, I post a photograph of the chart that we used in the previous class, and I ask for volunteers to walk us through the process of testing the viability of each answer.

If I'm teaching two different sections, I might have one section check the results of the other, cultivating a friendly little rivalry between the two classes.  I might also post the work of last year's class for comparison to ours.  We have a spirited discussion about how everything worked out, and this is a nice opportunity to students to share their conceptions and to surface their misconptions of what we've done so far.

I also have some notes prepared on today's Prezi.  I might use these, I might not: they're here if I realize they'll be useful.  On each slide, there are questions to guide conversations about each of the SLTs for this project, as well as the "Fascinating Chart". There are also a few basic example problems for finding unknown measurements in a right triangle; if I realize that students are ahead, or if they ask for reminders of how they originally learned to use the trig ratios, I might share some of these.

50 minutes

## Closing: Group Question

5 minutes
Here is the prompt:
• List all of the properties you know about similar triangles.
• How certain are you that your theoretical values are accurate? Why?

Now that students have had the chance to work on their projects, I pose this pair of questions and ask them to confer with their colored rectangle groups as they answer.  I collect their responses as they leave.