Need help on a math question

Question

The pilot of a helicopter measures the angle of depression to a landing spot to be 18.8 degrees. If the pilot's altitude is 1640 meters, what is the horizontal distance to the landing spot to the nearest meter?

Answer 1

Create an upside down right triangle with 18.8^o in the upper left, and 90^o in the upper right.    

The edge on the right side is the altitude, 1640.                                                                    

                                                                                                                                        

Use trig to find the top edge.

 

Since we are using the 18.8^o, and the opposide side and the top(adjacent) side, then tangent is the trig function to use.

 

Set up the equation:

 

tan ANGLE = opp. / adj 

 

tan 18.8^o = 1640 / x

 

To solve, multiply the left side by x and divide the right side by (tan 18.8^o).

 

x = 1640 / (tan 18.8^o)

 

x = 4817.47 meters