Trig Time

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SWBAT apply their knowledge of trigonometric ratios to find the values for sine, cosine and tangent.

Big Idea

Aiming for perfection with practice, what's your sine? Cosine and tangent too!

Do Now

10 minutes

In this Do Now  question, students review identifying the hypotenuse, adjacent side and opposite side given a specific angle.  As these key terms come from multiple lessons on triangles and relationships of lines, reviewing this prior knowledge is critical prior to beginning trig.  A possible extension I might use, depending on my students' needs, would be to also ask students to identify the opposite and adjacent side for angle C.  This lesson starter gets students prepared to see the use of repeated reasoning we will then use to calculate trigonometric ratios (MP 8).

Practice with Trig

30 minutes

Corners Activity

10 minutes

In this short kinesthetic 3- corner activity, the teacher has students identify when to use sine, cosine or tangent using examples.  You'll need to set-up or just identify verbally three corners of the room, to represent each  trig  function, sine, cosine or tangent.  As you show each question on the board, students move to the corner that represent which trigonometric function they should be using. Students get immediate feedback and enjoy the "competition". Depending on the time you have in class you can either provide the answer and/to solve the questions completely.

If you are limited in space or less comfortable with students moving about a modification would be to have students use notecard that say S, C or T and have hold these up as you post the examples. 

Using the 3-corner activity for formative assessment you might decide to scaffold the homework assignment by including some Corners Activity - Trig Time examples in the activity. 

Activity/Homework and Exit Ticket

20 minutes

The Activity-Homework provides students with an opportunity to practice today's topics of sine, cosine and tangent.  The first question provides scaffolded steps to help walk students through a practice example before trying questions on their own.  You can also use a gallery walk to review these questions for students, another fun way to have students learn from each other and compare their own work with their peers. 

The Exit Ticket asks students to calculate the sine and cosine given a right triangle. Students will need to use Pythagorean Triplets or the Pythagorean Theorem in order to find the length of the hypotenuse for this question; these are both pre-requisite skills for students.  To help scaffold this question (or if you are short on time), you can give students the length of the hypotenuse.