Trying to calculate percent slope (picture)

[needtrighelp]

First, here is the picture of the scenario:

It is known that the entire run is of length 6 (the vertical line is SUPPOSED to represent the mid point) thus either side is of length 3. The red angle is 4.5 degrees.

I am trying to calculate the slope as a percent of the blue angle, not the red angle. I know that by taking tan(4.5) that would give me the slope (rise/run) from the red angle but as I said that is not what I am interested in. If I knew the angle of the blue angle I could find its tan. but that value is unknown.

Thanks.

 

[tkhunny]

I know that by taking tan(4.5) that would give me the slope (rise/run) from the red angle but as I said that is not what I am interested in. If I knew the angle of the blue angle I could find its tan. but that value is unknown.

Thanks.

You're on the right track. Use your tangent to find the height. Use another tangent to find the angle measure of the blue.

 

[needtrighelp]

Okay, this is what I came up with:

tan(4.5) gives me rise / 6, so 6 times that gives me the rise which should be = .4722

Now I think I don't even need to know the other angle because I have the rise / run = .4722 / 3 = .1574 = 15.74% slope, does that work seem right?

 

[tkhunny]

Is that how one calculates such a thing? What does "as a percent of the Blue Angle" mean?