This Problem Set is a part of the Lesson 24, Unit 7, Grade 3. This is the first of four project-based lessons in which students create a robot and an environment for the robot using rectangles and circles. In this lesson, students plan the dimensions of each of the robot's body parts and surroundings. For example, given the requirement that the perimeter of the arms of the robot must be 14 inches, students experiment and draw different possibilities for rectangles to determine which ones they prefer for the robot's arms.