Using Trigonometry in CSI to analyse blood splatter

This is a lesson which I used at the end of the Trigonometry topic and includes the PowerPoint with two worked examples and full worksheet of mock crime scene blood. Have a look at the free version to see if this is right for your students.

This lesson looks at the use of Trig when looking at blood that was been ‘flicked’ at a crime scene. I go through two worked examples and then there’s a worksheet which has them doing 11 calculations split over 3 questions.

There are two questions which get the students to use the numbers to prove their findings. The second question asks them to explain how the small angle means it must have been flicked away from the body at a greater force showing this was an attack and not an accident.

The third gets them to show how three sets of stains have a similar angle and another three have a similar angle. This then proves the victim was hit once while standing and again while they were lower down which then proves the case.

This lesson needs limited explanation and allows lots of time for the students to have a go. I have put a ruler on the bottom just to help you when students don’t have them. Most of them just ripped it off and used them.

My school printer was able to print this with the ruler being accurate but some printers reduce the document but a few % which could give errors. If you find this then just remove the ruler from the bottom.