1. Warm up 1. Use the unit circle to find each value: – a. cos (-180 o ) – b. tan(45 o ) 2. Find the values of the six trig functions for angle in standard position if a point with coordinates (6, -5) lies on its terminal side.

2. Lesson 5-4 Applying Trig Functions Objective: To use the 6 trig functions to find the measures of the sides of right triangles.

3. Solving a Triangle USE YOUR CALCULATOR Set Mode to degree

4. Solving a Right Triangle If you know the angle but only one side you can find the other dimensions. cos 60 = 3 c Use calculator: cos 60 =.5.5 = 3 c C = 6 c a 3 A C β 60 o B

5. Try In a triangle ABC, α = 64 o, γ = 90 o, and b = 24.7 Solve the triangle.

7. eye - level

21. The angles are equal – they are alternate angles

22. Practice An observer in the top of a lighthouse determines that the angles of depression to two sailboats directly in line with the lighthouse are 3.5 o and 5.75 o. If the observer is 125 feet above sea level, find the distance between the boats.

23. Practice A regular hexagon is inscribed in a circle with a diameter 26.6 centimeters. Find the apothem of the hexagon.