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...
Lesson Plan
Curated OER

Basic Trigonometric Ratios

For Teachers 11th - 12th
In this trigonometric ratio worksheet, students determine the length of a side of a right triangle, or the measurement of angles using trigonometric ratios. This one-page worksheet contains 24 problems. Answers are provided at the bottom...
Worksheet
Curated OER

Finding Trigonometric Ratios

For Students 11th
In this finding trigonometric ratios worksheet, 11th graders solve and complete 22 various types of problems. First, they find the value of each trigonometric ratio to the nearest ten-thousandth. Then, students use a calculator to find...
Worksheet
Curated OER

Trigonometry Ratios in Right Triangles

For Students 10th
For this trigonometry ratios in right triangles worksheet, 10th graders solve 10 different trigonometric ratios that apply to right triangles. First, they define a trigonometric ratio and its three most common ratios, sine, cosine, and...
Unknown Type
Khan Academy

Khan Academy: Solve for an Angle in Right Triangles

For Students 9th - 10th Standards
Given two sides in a right triangle, find one of the acute angles using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Unknown Type
Khan Academy

Khan Academy: Solve for a Side in Right Triangles

For Students 9th - 10th Standards
Given one side length and an acute angle in a right triangle, find another side using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.