Area and Perimeter

• Same Perimeter, Different Area For Rectangles

  Students explore the big idea: Shapes can have the same perimeter, but very different areas.

  Show 3 Steps

  1. Students create at least five different rectangles with 16m of perimeter.

  2. They organize their information and look for a pattern between the shape’s dimensions and its area.

  3. Students create practical uses for three different rectangles made from sixteen meters of fence and explain their choices.

• Deducing the Area of Triangles

  Students will inductively determine the formula for the area of a triangle. Then we apply it to other, more complex shapes.

  Show 3 Steps

  1. Using examples, students will attempt to deduce the formula for the area of a triangle.

  2. We reveal the rule.

  3. Students attempt to decompose more complex shapes into triangles.

• Discovering Pi With Sticky Notes

  Students will experiment with sticky notes to find the area of a circle and, along the way, discover pi!

  Show 2 Steps

  1. First, students will cut up post-it notes, trying to see how many they can fit inside of a circle.

  2. Then, you can reveal that (if you had perfect precision) you could fit exactly π post-its into the circle.

• Exploring Circumference With Famous Circles

  Students will determine how the diameter and circumference of circles are related.

  Show 6 Steps

  1. Students investigate famous circles around the world and estimate how far it is to walk around versus across each circle.

  2. Next, they’ll measure across printouts of famous circles.

  3. Then, using string, they’ll measure around.

  4. Now, students will look for a relationship between the diameter and circumference.

  5. We reveal that the relationship is π.

  6. I explain a bit more about π.