SME
Grade 3 Math
Perimeter of polygons
The main lesson, then each kind of problem it solves.
Perimeter of polygons
Main lesson
Perimeter and unknown side lengths
Use this for “Three sides are 9 cm, 6 cm and 7 cm. The perimeter is 30 cm. How long is the fourth side?”
Same perimeter, different area
Use this for “Which rectangle has the same perimeter as this one?”
Same area, different perimeter
Use this for rectangles with the same area but different perimeters.
Perimeter of shapes with equal sides
Use this for “A sign has 8 equal sides of 12 inches. What is its perimeter?”