Education Technology


Math TODAY - When a Ruler Isn't Enough

Activity Overview

This activity illustrates a real-life problem that uses trigonometry to solve for an unknown. Students will use trigonometric ratios and inverse trigonometric relationships to determine the side of a triangle and the measure of the included angle.

Before the Activity

See the attached Teacher Edition PDF file for notes and guidelines for this activity. The Technology Guide PDF file includes step-by-step calculator instructions with screen shots.

If you are using the TI-Navigator™ Classroom Learning System, see the TI-Navigator Basic Skills Guide PDF file for information on how the system can be integrated into your activity.

During the Activity

Students will:

  • Use right triangle trigonometry to determine the measure of a side of the triangle given one side and an angle.
  • Use inverse trigonometric functions to determine the angle between two given sides.


  • Directions:
  • Distribute the Student Edition PDF file to your class.
  • Follow the activity procedures outlined in the student document.
  • You may use the Transparency PDF file to display a large image of the USA TODAY graphic during the activity.
  • After the Activity

    Distribute the assessment questions or send the attached LearningCheck™ assessment to your class to gauge student understanding of the concepts presented in the activity.