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...
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
Inverse Trigonometric Functions
Build on the understanding of finding angles using trigonometric ratios. Pupils develop the definitions of inverse trigonometric functions by restricting their domains in the 13th lesson of a 16-part series. They use inverse functional...
K20 LEARN
ADA Accessibility: Inverse Trigonometric Functions
Ramp up using trigonometric ratios. After receiving a request to check school ramps to verify they meet ADA requirements, groups calculate the angle of the incline on ramps on campus. They report their findings via a letter to the...
K20 LEARN
Round and Round We Go
Connect the dots on trigonometry with K'nex. Scholars use a K'nex model of a Ferris wheel to collect data points to plot on a height versus time graph. They'll then consider what type of function best models the data in the graph—and...
EngageNY
Revisiting the Graphs of the Trigonometric Functions
Use the graphs of the trigonometric functions to set the stage to inverse functions. The activity reviews the graphs of the basic trigonometric functions and their transformations. Pupils use their knowledge of graphing functions to...
EngageNY
Special Triangles and the Unit Circle
Calculate exact trigonometric values using the angles of special right triangles. Beginning with a review of the unit circle and trigonometric functions, class members use their knowledge of special right triangles to find the value of...
EngageNY
Law of Sines
Prove the Law of Sines two ways. The ninth segment in a series of 16 introduces the Law of Sines to help the class find lengths of sides in oblique triangles. Pupils develop a proof of the Law of Sines by drawing an altitude and a second...
EngageNY
Law of Cosines
Build upon the Pythagorean Theorem with the Law of Cosines. The 10th part of a 16-part series introduces the Law of Cosines. Class members use the the geometric representation of the Pythagorean Theorem to develop a proof of the Law of...
EngageNY
Addition and Subtraction Formulas 2
Knowing the addition formulas allows for the calculations of double and half formulas. The fourth installment of 16 has the class use the addition formula to develop the double angle trigonometric formulas. Using the double formula,...
EngageNY
Addition and Subtraction Formulas 1
Show budding mathematicans how to find the sine of pi over 12. The third lesson in a series of 16 introduces the addition and subtraction formulas for trigonometric functions. Class members derive the formulas using the distance formula...
EngageNY
Modeling with Inverse Trigonometric Functions 1
Where should I stand to get the best view? Pupils use inverse trigonometric functions to determine the horizontal distance from an object to get the best view. They round out the lesson plan by interpreting their answers within context.
Space Awareness
Navigating with the Kamal
Historians have proven that as early as 1497 skilled navigators were using a kamal to sail across oceans. Scholars learn about navigation tools and astronomy before building their own kamals. They then learn how to use it to determine...
EngageNY
Ferris Wheels—Tracking the Height of a Passenger Car
Watch your pupils go round and round as they explore periodic behavior. Learners graph the height of a Ferris wheel over time. They repeat the process with Ferris wheels of different diameters.