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...

Discover the classic example of periodicity: Ferris wheels. Young mathematicians learn about trigonometric functions through Ferris wheels. They match functions to their graphs and relate the functions to the context.

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...

Long considered the symbol of safe harbor and steadfast waiting, the lighthouse gets a mathematical treatment. The straightforward question of distance to the horizon is carefully presented, followed by a look into the...

Students measure angles using a plane table kit. In this geometry instructional activity, students use trigonometric identities to find the values of the length of a football field.

Learners determine the trigonometric relationships within a triangle as they construct a right triangle on the Ti-89. They find the sine, cosine, and tangent of various angles of their triangle construction.

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...

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.

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...

It's not just any circle—it's the unit circle. The fourth lesson in the series is an introduction to the famous unit circle. While working through a series of activities, young scholars learn the components of the unit circle and how to...

Students explore the concept of the six trigonometric functions, places where the functions can be utilized, and apply these functions to several electrical application problems.

Young scholars explore the concept of sine and cosine.  In this sine and cosine lesson plan, students work in groups to graph sine and cosine functions.  Young scholars examine how coefficients in various parts of each parent...

Start the exploration of trigonometry off right! Pupils build on their understanding of similarity in this instructional activity that introduces the three trigonometric ratios. They first learn to identify opposite and adjacent...

Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....

Concepts are only valuable if they are applicable. An informative resource uses concepts developed in lessons 26 and 27 in a 36-part series. Scholars write equations and solve for missing side lengths for given right triangles....

Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...

Students explore the concept of trig identities. In this trig identity lesson, students use Mathematica to graph trig identities. Students see the trig identities graphically and enforce the notion that two trig functions can be equivalent.

Students identify similar and congruent right triangles. In this geometry lesson, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.

Students perform transformation on trig functions. In this precalculus lesson, students relate the London Eye observation wheel to trig function. They use a TI navigator to visualise the parameter created by this view and relate it to...

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...

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...

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...

Trying to find a linear transformation is like finding a needle in a haystack. The second lesson in the series of 32 continues to explore the concept of linearity started in the first lesson. The class explores trigonometric, rational,...

Complex numbers were first represented on the complex plane, now they are being represented using sine and cosine. Introduce the class to the polar form of a complex number with the 13th part of a 32-part series that defines the...