This Instructional Activity is a part of the Lesson 3, Unit 9, Grade 6. This first activity helps students understand the geometric process that they use in later activities to connect the greatest common factor with related fractions. The first question helps students focus on the impact on side lengths of decomposing a rectangle into smaller rectangles. The second question has students analyze a rectangle that has been decomposed into squares. The third question has students decompose a rectangle into squares themselves.