Slide 4

First Step: Determining Angle of Impact:
As you can see from the image above, Finding the angle of impact does not involve much
in the way of advanced math. With basic trigonometry skills we can easily find
the angle given we knew the other variables like volume of the droplet.
The angle of the impact gives different lengths and tell-tale signs as seen below.

As you can see, as the blood strikes the surface at sharper angles, the tail gets longer,
giving us directionality. From there we would need to calculate where it came from.
This requires trigonometry in three dimensions as shown below.

Step Two: Determining Area of Convergence
Working this problem out for many different stains from the same source
and instant can lead us to know where the moment of trauma took place and can
even tell us facts about position of victim and attacker, such as was the victim kneeling
or standing as well as others.

Step Three: Determining Area of Origin
Using these equations to solve the problem, noting the w = width (green) and l = length (red), we
will end up finding the area of convergence. Finding the area of origin requires the third equation.
After finding the area of convergence , choose one stain to measure. And then, "

measure the distance from the
back-end of the stain to the area of convergence. Denote this distance by D. For this same droplet, compute
the angle of impact α. Let H denote the distance from the area of convergence on the surface to the area of origin."
(http://pi.math.cornell.edu/~numb3rs/jrajchgot/506f.html)

Area of Convergence	This is the term used to describe the area where two-dimensional lines drawn according to the angle of impact along the long axes cross each other, or converge.
Area of Origin	The term used of the area calculated to be location of causation for the spatter.