Curated OER
Basic Trigonometric Ratios
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...
EngageNY
Incredibly Useful Ratios
Start the exploration of trigonometry off right! Pupils build on their understanding of similarity in this lesson that introduces the three trigonometric ratios. They first learn to identify opposite and adjacent sides before exploring...
West Contra Costa Unified School District
Introduction to Trigonometric Functions
Scholars first learn the definitions of the sine ratio, the cosine ratio, and the tangent ratio. After mastering these definitions, they use the new information to solve triangles.
Curated OER
Finding the Area of an Equilateral Triangle
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...
EngageNY
What Is a Trigonometric Identity?
Protect yourself from identity theft! Establishing a strong understanding of the Pythagorean identity allows learners to prove that sine^2x + cos^2x = 1. They then use the identity to find sine or cosine ratios given the other.
Curated OER
Trigonometry Ratios
Students identify the different angles and sides of a triangle. In this geometry instructional activity, students identify the six trigonometric ratios. They graph the graph of each trig function and analyze it.
EngageNY
Trigonometry and the Pythagorean Theorem
Ancient Egyptians sure knew their trigonometry! Pupils learn how the pyramid architects applied right triangle trigonometry. When comparing the Pythagorean theorem to the trigonometric ratios, they learn an important connection that...
Curated OER
How are Trig Ratios Used to Measure Triangle Sides
Young scholars identify the ratios of trig identities. In this geometry lesson, students solve the missing sides and angles of triangles using trig ratios. They relate the graphs and waves to real life scenarios.
EngageNY
The Definition of Sine, Cosine, and Tangent
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar triangles.
EngageNY
Sine and Cosine of Complementary Angles and Special Angles
Building trigonometric basics here will last a mathematical lifetime. Learners expand on the previous lesson in a 36-part series by examining relationships between the sine and cosine of complementary angles. They also review the ratios...
Curated OER
Ratios in Right Triangles
Learners calculate the sides of right triangles in this trigonometric ratios instructional activity. They use Cabri Jr. software and TI-83 or TI-84 calculators to find the side lengths and their ratios to each other for various...
Curated OER
The Tangent Ratio
Students calculate the tangent ratio given a right triangle. In this trigonometry lesson, students use a right triangle and the Pythagorean Theorem to solve problems.
Curated OER
Does Your Field Measure Up
Learners measure angles using a plane table kit. In this geometry lesson, students use trigonometric identities to find the values of the length of a football field.
Curated OER
Trigonometric Ratios
Young scholars measure and analyze angles. In this trigonometry lesson, students measure angles and distances use non-traditional techniques. They identify the different ratios of sine, cosine and tangent.
Virginia Department of Education
Special Right Triangles and Right Triangle Trigonometry
Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...
EngageNY
Unknown Angles
How do you solve an equation like trigonometry? Learners apply their understanding of trigonometric ratios to find unknown angles in right triangles. They learn the meaning of arcsine, arccosine, and arctangent. Problems include basic...
Curated OER
Trigonometric Functions of Acute Right Triangles
Students derive the six trigonometric functions. In this trigonometry lesson, students show their understanding of trigonometric functions as they relate the right triangles. They find the missing angles and side use trig ratios of sine,...
Curated OER
Trig is SOH Easy!
Students derive the six trigonometric identities. In this trigonometry lesson plan, students review the parts of a right triangle and use the Pythagorean theorem as a guide to find the trig identities. They find sine, cosine and tangent...
Alabama Learning Exchange
"I Saw the Sine"
Discover trigonometric ratios that complement each other. Using two videos, the lesson introduces the trigonometric ratios. The class discovers the relationship between the sine and cosine of complementary angles.
Project Maths
Introduction to Trigonometry
The topic of trigonometric ratios is often covered with loads of rote memorization baked into the activity. This activity set, however, leans more on using similar triangles and discovery learning to help young geometers develop a deeper...
Curated OER
Understanding Fundamental Trigonometric Identities
Young scholars are introduced to the basic trigonometric identities. Using a diagram, they discover why the parts of the unit circle as named as they are and use equations to finalize the Pythagorean trigonometric identities. They also...
Curated OER
Introducing Trig
Fifth graders explore the importance of triangles in the real world. They find the unknown side of a right triangle using a scale drawing. Students use Pythagoras' Theorem and other appropriate ratios.
Curated OER
Geometry Exploration Basic Trig Functions
Tenth graders solve for missing sides on a triangle using the Pythagorean Theorem. In this geometry lesson, 10th graders are introduced to basic trigonometry functions as they solve problems of right triangles. They discuss the formulas...
EngageNY
Between-Figure and Within-Figure Ratios
Tie the unit together and see concepts click in your young mathematicians' minds. Scholars apply the properties of similar triangles to find heights of objects. They concentrate on the proportions built with known measures and solve to...