This Fluency Activity is a part of the Lesson 3, Unit 2, Grade K. This is a preparatory fluency activity intended to review the previous lesson's work with triangles and prepare students to name and identify rectangles in a similar manner. I'll show you a shape. We'll try to decide if it's a triangle or not. If you think it's a triangle, give me a thumbs-up. If it's not a triangle, thumbs-down.