Created on: September 20, 2008

Website Address: https://library.curriki.org/oer/Lesson--Applying-the-sine-and-cosine-ratios

TABLE OF CONTENTS

- Curriki Project Based Geometry
- Curriki Calculus: Applications of Derivatives
- Curriki Calculus: Integrals

- Designing a Winner Resources
- Curriki Geometry Tools and Resources
- Problems -- Similarity
- Designing a Winner Teacher Edition
- Designing a Winner Student Edition
- Lesson -- Applying the sine and cosine ratios
- Equation of a tangent line
- Cabo SUP Challenge
- Similarity Tutorial
- ShowMe.com Reflection Videos

- Selling Geometry
- Designing a Winner
- What's Your Angle, Pythagoras?
- TED Talk: House of the Future
- The Art of Triangles
- How Random Is My Life?
- Introduction to Angles
- Lesson -- Drawing right triangles from word problems
- Accessing Curriki Geometry Projects
- Introduction to Curriki Geometry

- Lancaster Multipurpose Arena
- Southaven Multipurpose Arena
- Illinois Multipurpose Arena
- University of Virginia Multipurpose Arena
- 3XN Multipurpose Arena
- Football Field Dimensions
- Bleacher Systems
- Design Process Manual
- Khan Academy Resources
- Geometry Vocabulary Test
- Cabo SUP Challenge
- ShowMe.com Reflection Videos
- Problems -- Similarity
- Similarity Tutorial
- Lesson -- Applying the sine and cosine ratios

Aim: How do we find the sine and cosine ratios in right triangles?

Learning objectives: Students will be able to express the sine and cosine of an angle as a ratio. Students will be able to find missing side lengths for any right triangle.

Prerequisite knowledge: Students should know how to write tangent ratios. Students should know how to solve for a missing leg given the length of the other leg.

Motivational problem: 1. B = 37°, C = 90°, b = 12, a = ? 2. A = 90°, B = 70°, b = 10, c = ?

Key ideas: SOHCAHTOA sine = opposite/hypotenuse, cosine = adjacent/hypotenuse. The hypotenuse is the longest side in a right triangle and is always opposite the right angle. The opposite and adjacent angles depend on the angle being measured.

Important questions: When is the sine ratio the biggest? When is the sine ratio the smallest? When is the cosine ratio the biggest? When is the cosine ratio the smallest? How are the sine, cosine, and tangent ratios related?