By using body parts and sightlines to find the distance to an object, students can reinforce the study and application of similar triangles. This activity is a good combination of tactile learning, practical application, careful observation and modeling, and higher-order thinking. The teacher may subsequently pursue the material in greater depth or use it as a starting point for excursions into other fields of study.
Michael Wong, firstname.lastname@example.org, has taught and tutored several different subjects in various countries. This article began as a lesson for his active, thoughtful students in the Caribbean. Now retired, he taught most recently in Brazos High School, Wallis, TX 77485.