Step 2: The Risers
Due to the complication in these indoor staircase calculations I'm going to refer to a free online stair calculator. as well I'll post this detailed diagram.
for uncomplicated staircases and once you have your lenghth and angle calculations this is how you measure and cut a riser.
1. take the board you are using for the riser and measure the angle to the bottom left corner and draw a line.
2. measure your rise height from the line in step 1 to the edge of the board and draw a line.
3. measure from the run length from the rise point 90 degrees and draw a line
See Diagram #2
cut out all the lines drawn and then make a duplicate, and triplicate depending on step width.