# Activities

• • • ##### Subject Area

• Math: Geometry: Triangles
• Math: Precalculus: Trigonometry (Triangle and Circular Functions)

• ##### Author 9-12

60 Minutes

• ##### Device
• TI-30X IIB
• TI-30X IIS
• TI-34 II Explorer Plus™
• ##### Other Materials
This is Activity 9 from the EXPLORATIONS Book:
Math Investigations with the TI-30X IIS: Activities for Secondary Mathematics

• ##### Report an Issue

Computing by Degrees!

#### Activity Overview

Students use the calculator to solve trigonometry problems using sine, cosine, and tangent. They also find inverses of trigonometric functions.

#### Before the Activity

• Set the angle mode of the calculator to degrees
• See the attached PDF file for detailed instructions for this activity
• Print pages 87 - 90 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.

• Understand the relationship between the sides and angles of a right triangle
• Calculate the length of a side of a right triangle, given the angles and length of at least one side

• Use the calculator to find the decimal form of the sine of an angle given in degree-minute-second form

• Understand how to calculate the angle of depression by identifying a trigonometric ratio, and using the corresponding equation

• Use the formulas of the trigonometric ratios to solve problems
• #### After the Activity

Students complete the Student Activity pages.

• Review student results
• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary