Porch Steps Decisions and Calculations

We need some porch steps.

I may have finally found some pavers I like for them!!!  I have looked all around at places and there are SO many choices and styles.  I think these will work and look the best.

source: Lowe's

They measure roughly 15x24 inches.

Now I just need to figure out how many I need. 

I found this cool site: (link: http://www.gardengatemagazine.com/64stepchart/) that had a handy dandy chart to easily figure out treads and risers.  I want my treads to be 15 inches wide so my risers need to be between 5½-6 inches high and I would like the whole thing to be 6 feet wide.

Ok.  Got that figured out.

Now to figure out how many steps there will be.

On this site (link: http://www.wikihow.com/Build-Porch-Steps) I found this:

source

And since I couldn't really measure the height because of the slope of rocks,

I decided to check out this site,

(link: http://inspectapedia.com/Stairs/Stair_Calculations.php).

I read this section called 

The Mathematical Approach to Building Stairs Spanning Uneven Ground

This is how it started out:

Quote: The geometry approach to calculating stair rise and run over rough terrain when you have only two measurements works correctly provided you know enough triangular geometry to convert between your sloped-line measurement (the hypotenuse of the triangle) and the triangle's other sides that form the rise & run dimensions. Using a calculator and it's square root function, and the most basic knowledge of geometry is not enough - we also need a table of sine and cosine values, functions readily found these days online. [45]

 a2 =b2 +c2 - the square of the length of the hypotenuse (a) equals the squares of the lengths of the opposite sides of a right triangle (b) and (c).

And I said- Oh yes!  That is as clear as mud!
My eyes totally glazed over and I stopped reading right there.

  AND I ACTUALLY TOOK CALCULUS AND TRIG AT SCHOOL.

Must have been about a hundred years ago though because I can't remember A THING.  I guess I will be going forward with rough eyeball estimates.  If I start out at the top and go down I can always adapt the dirt at the bottom to be higher or lower.  Right??????  Much easier than math.

Then I reread the article and they were only kidding. 

They actually say to do this:

source

Ok.  Whew!  Much more sensible!!!

Who knew engineers had a sense of humor.

I need to find some long boards.
I know what plumb means but to achieve it????
Might take awhile....

Now I also need to figure out what the risers need to be made out of....

For some reason I thought I would be able to whip these out in a couple of days.