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...
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.
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
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...
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
Trigonometry Ratios
Students identify the different angles and sides of a triangle. In this geometry lesson, students identify the six trigonometric ratios. They graph the graph of each trig function and analyze it.
Curated OER
Ratios in Right Triangles
Learners calculate the sides of right triangles in this trigonometric ratios lesson plan. 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 triangles. The...
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
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...
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...
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
Students measure angles using a plane table kit. In this geometry activity, students use trigonometric identities to find the values of the length of a football field.
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.
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...
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...
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
Trig is SOH Easy!
Students derive the six trigonometric identities. In this trigonometry lesson, 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 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 plan, 10th graders are introduced to basic trigonometry functions as they solve problems of right triangles. They discuss the...
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...
Curated OER
Trigonometric Ratios
Pupils measure and analyze angles. For this trigonometry lesson, students measure angles and distances use non-traditional techniques. They identify the different ratios of sine, cosine and tangent.
Curated OER
Exploring Trigonometric Ratios
Students calculate the different ratios using a right triangle. In this trigonometry instructional activity, students identify the sine, cosine and tangent of each side. They find the missing angles using the different ratios.
Curated OER
How are Trig Ratios Used to Measure Triangle Sides
Students identify the ratios of trig identities. In this geometry lesson plan, students solve the missing sides and angles of triangles using trig ratios. They relate the graphs and waves to real life scenarios.
Curated OER
Investigating Trigonometric Ratios Through Similar Right Triangles
Students identify similar and congruent right triangles. In this geometry activity, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.