This document provides instruction on using trigonometric ratios to find missing sides or angles of right triangles. It defines the sine, cosine, and tangent ratios, and gives examples of using them to solve for unknown side lengths or angles. Students are assigned a worksheet to complete problems using trigonometric ratios to find missing parts of right triangles.

1. Warm-up:
Find the missing sides of the triangles.

2. Expanding with Special Triangles:

3. 8.3-8.4 Trigonometric
Ratios
Objective: Use the sine, cosine, and
tangent ratios to find missing sides of
a right triangle.
Standard: Geometry 19.0

4. The Three Ratios:
Sine Ratio- compares
______ to ______ A
Cosine Ratio- compares
______ to ______
Tangent Ratio- compares
______ to _______
Abbreviations:
sine = _____ cosine = _____ tangent = _____

5. Here's how to remember…
A

6. Writing Ratios
Ex. 1) Find the following trigonometry
ratios.
a) sin A =
b) cos E =
c) cos C =
d) tan A =
e) tan D =

7. Assignment:
#8 SOH-CAH-TOA Ratios
WS

8. Finding Missing Sides
Ex. 2) Solve for x.
20
x
35°

9. Finding Missing Sides
Ex. 3) Solve for x.
x
42°
9

10. Finding Missing Sides
Ex. 4) Solve for x.
73° x
18

11. Finding Angles
How can we find the angle if we have the
sides?

12. Finding Missing Angles
Ex. 5) Solve for x.
x° 31
18

13. Finding Missing Angles
Ex. 6) Solve for x.
8
x°
14

14. Assignment:
#9 8.3 and 8.4 WS
(Workbook p. 401, 403)
Skip 10-12 on 8.3