This Instructional Activity is a part of the Lesson 13, Unit 2, Grade 8. This activity could be done on a sunny day. You should try it out ahead of time to ensure that the shadows created in your part of the world at the time your class takes place are cooperative! Either find a tall object outside that all students will find the height of, or let students choose a tall object. It should be tall enough that its height can't be easily measured directly, on level ground, and perpendicular to the ground. Students head outside with tape measures (or other measuring devices) and use what they've learned in this lesson to figure out the height of the tall object.