The purpose of this activity is for students to understand that many different shapes can have the same perimeter. Students start to focus more specifically on shapes with repeated side lengths, so they can leverage the efficient addition strategies elicited in the Warm-up (MP7).

• “¿Cómo encontraste el perímetro de esta figura?” // “How did you find the perimeter of this shape?”
• “¿Qué otras estrategias puedes usar para no tener que contar las unidades una por una?” // “What other strategies could you use so you wouldn’t have to count one unit at a time?”

• Invite students to share a variety of methods for finding the perimeter of the different shapes. Ask students who found the perimeter of shapes in efficient ways to share their reasoning.
• Consider asking: “¿Alguien encontró el perímetro de otra manera?” // “Did anyone find the perimeter in a different way?”
• “Las figuras A y G se ven muy diferentes, pero sus perímetros tienen la misma longitud. ¿Cómo es posible?” // “Shapes A and G look very different but have the same length for their perimeter. How could that be?” (The shapes may look different but the distance around each is the same number of units. Different shapes can have the same perimeter.)

The purpose of this activity is for students to draw shapes with specific perimeters. Students may create any shape that uses horizontal and vertical lines. Since diagonal lines that connect the dots are not one length unit, students cannot find the perimeter of shapes that include diagonal sides. Encourage students to be creative in drawing their shapes to reinforce the idea that different shapes can have the same perimeter.

• Select previously identified students to share their strategies for drawing shapes for one of the perimeters in the first problem.
• “¿Qué perímetro escogieron con su compañero para dibujar la figura? ¿Por qué escogieron ese número?” // “What perimeter did you and your partner choose to draw a shape for? Why did you pick that number?”