Education Technology

Special Ratios and the Unit Circle

Published on 06/09/2008

Activity Overview

These StudyCards™ stacks test the students comprehension of trigonometric ratios in a unit circle. They are tested on their ability to find the value of angles from trigonometric ratios of positive numbers, negative numbers, and radians as ratios of π.

Before the Activity

Download the TI StudyCards Creator Software on the calculator using one of these two methods:

  • TI Connect™, a TI Connectivity Cable, and the Unit-to-Unit Link Cable
  • TI-Navigator  send to class feature


  • Review the StudyCards files prior to class.
    Make sure the StudyCardApp is on all student calculators.

    Transfer the StudyCard files to student calculators using one of these methods:
  • StudyCard Creator send to device feature with a connectivity cable and unit-to-unit cables
  • TI-Navigator System send to class feature
  • During the Activity

    This activity is intended as a learning review. Students may work alone or in small groups You may wish to circulate the room to answer students' questions.

    StudyCards™ Stack 1 tests the students comprehension of trigonometric ratios in a unit circle. They are tested on their ability to find the value of angles from trigonometric ratios (sine and cosine) of positive numbers, negative numbers, and radians as ratios of π.

    StudyCard Stack 2 tests the students comprehension of trigonometric ratios in a unit circle. They are tested on their ability to find the value of angles from trigonometric ratios (sine, cosine, and tan) of positive numbers, negative numbers, and radians as ratios of π.

    StudyCard Stack 3 tests the students comprehension of trigonometric ratios in a unit circle. They are tested on their ability to find the value of angles from trigonometric ratios (sine and cosine) involving π in radians and numbers.

    StudyCard Stack 4 tests the students comprehension of trigonometric ratios in a unit circle. They are tested on their ability to find the value of angles from trigonometric ratios (sine, cosine, and tan) involving π in radians and numbers.

    After the Activity

    Review student results:

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