Algebra II LP set 43,44
From Brush Schools Wiki
Class: Algebra II
Lesson: Sine, Cosine, and Tangent
Objective: Students will use sine, cosine, and tangent to find missing parts in right triangles.
Standard: 4.4a Use right triangle trigonometry* to solve real-world problems. ES
Procedure:
- Prior knowledge
- Definition of right triangle: A triangle with a right angle.
- ratio
- New information
- Definition of the three basic trigonometry functions
- On a scientific calculator, locate the sin, cos, and tan keys.
- On a scientific calculator, locate the sin^-1, cos^-1, and tan^-1
- When finding sin, cos, or tan of an angle, the answer will be a ratio. (note: the calculator will give the answer as a decimal number)
- When finding sin^-1, cos^-1, or tan^-1, the answer will be the measure of an angle.
- Calculators will give answers for angles in degrees or radians. For now, we will work with degree measure.
- Connect prior knowledge and new information
- connect side ratios with angles associated with sine, cosine, and tangent.
- Example
- Construct a right triangle and indicate the given information. Side a is 3, side b is 4, and the hypotenuse is 5.
- Find sin A, cos A, and tan A. Write the answers as ratios
- Find sin B, cos B, and tan B Write the answers as ratios
- Using a scientific calculator, find sin 27, cos 27, and tan 27
- Depending on the calculator, enter sin27 =.4539904997
- or enter 27 sin = .4539904997
- cos72 = .8910065242 and tan27 = .5095254495
- Find an angle whose sin is .27561
- shift (2nd) sin .27561 = 15.99836947 (degrees) or .27561 shift (2nd) sin = 15.99836947 (degrees)
- Find an angle whose sin is .27561
Conclusion: Construct a right triangle and indicate one angle with a measure between 1 and 89 degrees. Label two sides with numbers and find the length of the other side and the missing angle.
- Note: “If the teacher summarizes, it’s the teacher who gets the benefit of the closure exercise, not the student.” Jane E. Pollock Improving Student Learning One Teacher at a Time.
Student practice and more examples if needed:
- Set 43 numbers 6,7, and 8
- Set 44 number 6
- right triangle trigonometry practice word problems
Resources:
