3 As the video states, in order to find the angle of impact: “the analyst measures the length and the width of each stain, and calculates the angle of impact using simple trigonometry.” The following formula is used to find the angle of impact: Angle of Impact = Arc Sin (width/length)
The analyst will start by measuring the width and length of a bloodstain. They will then divide the width of the splatter by the length. Finally, they will determine the ArcSin of that number (this can be done by using a calculator with the arcsin function). For example, if a blood spot had the width of 9mm and the length of 18mm:
Arcsin (9mm/18mm) = 30 degrees
The angle of impact of that spot would be 30 degrees
Why are trigonometry functions such as this important in forensic science?