## Reflection: Developing a Conceptual Understanding Developing the Unit Circle - Section 2: Using special triangles to evaluate trigonometric functions

During this section of the lesson I was able to see how the material and time spent earlier in this unit helped students understand concepts. Students were quick to realize how to use the special triangles to find the trigonometric values for angles greater than 90 degrees.

The students may not have remembered that the angle to the x axis is called the reference angle but they were willing to use the idea to find what was asked.  I feel the activity over the last 2 days made today's lesson go smoothly.

The main struggle for today was making sure students drew the triangles to the x-axis. Some students had drawn triangles to the y-axis. I reminded students that we measure the angle at the origin and that this angle would change the opposite and adjacent sides. By drawing to the x-axis the x coordinate is the adjacent leg and the y coordinate is the opposite leg. When you draw the triangle to the y-axis this switches.

Connecting previous activities
Developing a Conceptual Understanding: Connecting previous activities

# Developing the Unit Circle

Unit 7: Trigonometry as a Real-Valued Functions
Lesson 7 of 13

## Big Idea: How can right triangles and reference angles help find the values on the unit circle?

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Standards:
Subject(s):
Math, Trigonometric functions, unit circle, special angles, radian measure
40 minutes

### Katharine Sparks

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