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...

Students 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.

Using PVC pipe and aquarium tubing, build an altitude tracker. Pupils then use the altitude tracker, along with a tangent table, to calculate the altitude of a launched rocket using the included data collection sheet.

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...

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...

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...

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...

The class gets to practice being a mathematician in ancient Greece, performing geometric application problems in the way of Eratosthenes. After following the steps of the great mathematicians, they then compare the (surprisingly...

Proving a trig identity might just be easier than proving your own identity at the airport. Learners first investigate a table of values to determine and prove the addition formulas for sine and cosine. They then use this result to...

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...

Here is a basic plan for the beginning teacher to use for introducing the class to the right triangle trigonometric functions. It outlines the lesson objectives, class procedures, and basic instructional techniques that could be...

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

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....

Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.

Round and round we go! Pupils use reference angles to evaluate common sine and cosine values of angles greater than 360 degrees. Once they have mastered the reference angle, learners repeat the process with negative angles.

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.

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.

Students calculate the six trigonometric identities. In this algebra lesson, students verify other identities using the basic trigonometric identities of sine, cosine and tangent. They complete a worksheet with hints and then are graded...

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,...

What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...

Learners solve problems using trigonometric functions, specifically a problem about a tree stand. Pupils try to maximize the distance of hunting sight given certain restrictions. They use the Pythagorean Theorem, sine, cosine, and...

Learners explore circles using a graphing calculator. In this circles lesson, students write the equation of a circle with a given center and radius length. Learners find the most appropriate model for each combination of data they...

The concept of sine and cosine is explored in this lesson plan where high schoolers graph sine and cosine graphs using a transformation application on the graphing calculator.  Students change the coefficients for the amplitude,...

After determining the volume of various drinking glasses , class members evaluate sample responses to the same task to identify errors in reasoning.