8.5. Tangent, Sine and Cosine http://www.ck12.org
8.5 Tangent, Sine and Cosine
Learning Objectives
- Use the tangent, sine and cosine ratios in a right triangle.
- Understand these trigonometric ratios in special right triangles.
- Use a scientific calculator to find sine, cosine and tangent.
- Use trigonometric ratios in real-life situations.
Review Queue
- The legs of an isosceles right triangle have length 14. What is the hypotenuse?
- Do the lengths 8, 16, 20 make a right triangle? If not, is the triangle obtuse or acute?
- In a 30-60-90 triangle, what do the 30, 60, and 90 refer to?
- Find the measure of the missing lengths.
a.b.Know What?A restaurant needs to build a wheelchair ramp for its customers. The angle of elevation for a ramp is
recommended to be 5◦. If the vertical distance from the sidewalk to the front door is two feet, what is the horizontal
distance that the ramp will take up(x)? How long will the ramp be(y)? Round your answers to the nearest hundredth.