This activity gives students a "hands-on" and real-life approach to indirect measurement. Print out the 12 pictures from this PowerPoint show. Students use a ruler to measure the lengths of 2 objects. The actual length of one of the objects is given. Students must write and solve a proportion to find the length of the other object. The answer key is included in the PowerPoint along with a student worksheet. Note: Answers will vary slightly due to discrepancies when measuring.