Trigonometric Ratio              

                     Lesson 1

Problem:  In a ∆ABX, AB = 45 and ‹B= 47° Find XB

Solution    In right triangle ABX,

Step 1:

Solution    Hypotenuse AB = 45 and angle B = 47º.

Step 2:

Solution   Cos B = Base / Hypotenuse

Step 3:  

                                                            Solution   Cos A = XB / AB

Step 4:

Solution    Cos 47° = 45 / AB

Step 5:

Solution    Answer = 64.3

Step 6:

Complete

                                                            Try two practice problems:

A.

In a ∆HRD, HR = 15 and ‹D= 35° Find RD

B.

In a ∆MNB, MN = 23 and ‹M= 29° Find BM

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