1. Lesson 13.1: Trigonometry

2. Objectives
Understand and use trigonometric relationships of acute angles in triangles.
Determine side lengths of right triangles by using trigonometric functions.

3. Relevance
Trigonometry can be used to measure the heights of objects, such as an eruption of a geyser, that cannot be measured directly.

4. Definitions Trigonometry – Greek word meaning “ triangle measurement”
Trigonometric Function – a function whose rule is given by a trigonometric ratio.
Trigonometric Ratio – ratio comparing the lengths of two sides of a right triangle.
 (“theta”) – used to represent the measure of an acute angle in a right triangle.

5.  

6. Trigonometric Ratios

7. Ex. Find the sine, cosine, and tangent.25 7  24

8. Three more Trig Ratios
Cosecant
Secant
Cotangent