This Problem Set is a part of the Lesson 1, Unit 8, Grade 8. The Areas of Squares and Their Side Lengths Let's investigate the squares and their side lengths. Learning targets: students can find the area of a triangle and the area of a tilted square on a grid by using methods like "decompose and rearrange" and "surround and subtract." Required Preparation: 1 copy of the Making Squares blackline master, pre-cut, for every 2 students.