Lesson Plan
Curated OER

Finding the Area of an Equilateral Triangle

For Teachers 9th - 11th Standards
The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...
Activity
Windstream

Ojk World of Math: Relationships Between the Functions

For Students 9th - 10th Standards
This tutorial discusses relationships among all the trig identities. Examples are given on how to apply them to simplify trig expressions and prove identities.
Activity
Texas Instruments

Texas Instruments: Basic Trigonometry Love or Leave It!!

For Teachers 9th - 10th
This activity has the teacher to create 3 triangles on Cabri Jr. on the TI-83 or TI-84. It will prove to students how trigonometry ratios are found. It will show to the students where the ratios are derived rather than just telling the...