This activity is intended to supplement Trigonometry, Chapter 1, Lesson 3.
In this activity, you will explore:
Sine, cosine and tangents of angles
Side length ratios of a right triangle
Finding the missing side of a triangle when an angle and side are given.
Before beginning this activity, make sure your calculator is in DEGREE mode. Press the MODE button, arrow down two lines, arrow to the right to select DEGREE, and press ENTER.
Problem 1 – Trigonometric Ratios
Start the CabriJr app by pressing the APPS button and choosing it from the menu.
Select Open from the F1: File menu, and choose the file TRIG.
In right triangles, there is a relationship between the ratios of the side lengths and the trigonometric functions.
Repeat this for two more different triangles by moving point B to a different location (to grab a point, press the ALPHA button and use the arrow keys to move it.)
Based upon your answers hypothesize which ratio goes with each trigonometric function.
A good acronym to use to help remember these relationships is SOHCAHTOA
Problem 2 – Trigonometry, What Is It Good For?
One of the uses of trigonometry is finding missing side lengths of a triangle.
Write the correct trigonometric function for each triangle below and solve for the missing side.