- The students each find the tangent ratios for each angle in each of the three triangles.
- Once this is completed, ask them to compare their answers with the chart which gives the angle measure for
different special triangles. - Have the students note if any of the triangles drawn fall into the category of these special triangles.
- When finished, ask the students to check each other’s work.
- Allow time for whole class feedback.
- Intelligences- linguistic, logical- mathematical, visual- spatial, interpersonal
III.SpecialNeeds/Modifications
- Write on board “Trigonometric ratios show the relationship between the sides of a triangle and the angles
inside it.” - Define Tangent Ratio- of an angle is
Tanx=Length of opposite sideLength of adjacent side
- Thexrefers to the angle we are focused on.
IV.AlternativeAssessment
- Collect student work and use the triangles to assess student understanding.
- Listen to student comments following the activity.
- Allow time for student questions.
Sine and Cosine Ratios
I.SectionObjectives
- Review the different parts of right triangles.
- Identify and use the sine ratio in a right triangle.
- Identify and use the cosine ratio in a right triangle.
- Understand sine and cosine ratios in special right triangles.
II.MultipleIntelligences
- To differentiate this lesson, teach the material in the lesson and then complete a “working backwards” activity
with the students. - In the last lesson, we worked with a right triangle and wrote out the tangent ratios for the angles in the triangle.
- In this lesson, we are going to start with the cosine and sine for the different angles of a right triangle. Then
the students need to take these ratios and design a triangle that matches the ratios. - In this way, the activity is called “working backwards.”
- The angles of the triangle areA,BandC.
- sinA=^67
- sinB=^57
- cosA=^57
- cosB=^67
- Allow time for the students to work with these ratios and draw a right triangle that matches the ratios.
- When finished, allow time for student sharing.
- Intelligences- logical- mathematical, linguistic, visual- spatial, interpersonal, intrapersonal.
4.8. Right Triangle Trigonometry