This week we focused mainly on finding angles in a triangle. This could be the angle of depression, the angle of elevation, or finding out an unknown reference angle.
Reference Angle:
- First, we need to start with our triangle and label each side accordingly, since the reference angle is unknown, we have to work backward kind of.
- Second, we need to find out which function we’re using. Listing them off helps (SOH CAH TOA) Since we don’t have the hypotenuse or reference angle, we can’t use sine or cosine. So, tangent is the only choice left. Write out the ratio for the tangent of unknown angle x.
- Third, change tan to the second function on your calculator, and divide the adjacent side by the opposite side.
- Lastly, solve the equation by dividing (A/0) and write the final statement. For this question, angle x would equal to be about 61 degrees.
The angle of Elevation and Angle of Depression
The angle of Elevation-The angle of elevation is the same as the angle up. To elevate means to lift, so it’s the angle that lifts up.
In this example, the dot on the horizontal line would equal to you, or a person. The dotted line is the sight line up to an object, which ultimately creates an angle of elevation. The object is the other dot, and the angle of elevation is what is created from the horizontal line and the sight line.
The angle of Depression-The angle of depression is the same as the angle down. To make a depression means to go down, so it is the angle that is facing downwards if that makes sense.
In this example, the dot on the horizontal line would again equal to you or an observer. The dotted line is, again, the sight line down to an object, which again creates an angle of depression. The only difference between depression to elevation is that one, the depression, is an angle that is diagonally declining down on an angle, while the elevation is inclined on an upward angle. The object is the other dot, which is connected by the sight line.