Education Technology

Law of Sines

Published on 10/17/2008

Activity Overview

In this activity the student will explore the Law of Sines, a theorem involving sine ratios that applies to all triangles.

Before the Activity

Teacher preparation
Download the attached .Doc or .PDF documents and the TI_Nspire document.
You will need to copy the .tns document to students' handheld before the exploration.
Read activities in advance.

During the Activity

Classroom management tips

  • Be prepared to guide students during the exploration.
  • Encourage students to look for patterns, make connections, and share their findings during the exploration.
  • After the Activity

    Assessment and evaluation

  • Evaluate students' conjecture written on page 1.4 of their TI_Nspire document.
  • Make students write about their findings and support their findings in observations done during the exploration.


  • Activity extensions
  • Students can use the law of sines to find the sides lengths and angle measures of a triangle.
  • Students can determine the area of a triangle given side-angle-side information
  • Connections to other content areas to explore: sail makers can use sine ratios to determine the amount of fabric needed to make a sail.