# Investigation: Sketch a crime scene using geometry

Lesson

Imagine you're a detective for your local police agency.  You've just arrived at the scene of the crime, only to find out that you need to record everything exactly as it appeared.  You don't have time for detailed sketches, but you know that the lengths and angles, and locations of the objects are crucial in solving the crime.  What will you do?  Draw a sketch of the scene using geometry!

## Objective

• Use geometric shapes, their measures, and their properties to sketch the scene of a crime

## Materials

• pencil & paper for recording measurements and drawing sketches
• protractor
• measuring tape

## Procedure

1. In a group of 2-3, think of a scenario and stage a pretend crime scene using objects from your classroom.
2. Agree on a point of view for everyone in the group to draw the sketch (e.g. view from directly above, side view, etc).
3. Draw a diagram using geometric shapes to depict the important objects and locations in your crime scene (e.g. the location of a missing object represented as a point or a desk viewed from above represented as a rectangle).
4. Measure and record all distances, angles, and lengths of important objects and locations in the crime scene.  Note them in your diagram.
5. Clean up your crime scene.
6. Trade crime scene sketches with another group.  See if you can interpret or recreate the crime of the other group without viewing the original scene.

## Questions for Reflection

1.  In what ways did simplifying your crime scene with geometry make the scene easier to understand?  In what ways did it make it more difficult?

2.  After hearing the explanation of the other group's crime, what kinds of details do you think would be helpful for them to add (or take away)?

3. What other situations can you think of that might be summarized using geometric diagrams?  Explain and sketch them out.

### Outcomes

#### GEO-G.MG.1

Use geometric shapes, their measures, and their properties to describe objects.