Grade 4 · Spatial Sense · Lesson 2
Find a Missing Side
If you know a rectangle's area and one side, division reveals the missing side.
Worked example
A garden has an area of 35 m²
One side is 7 m. How long is the missing side?
Area relationshipside × side = area
Use division35 ÷ 7 = 5
Missing side5 m
Check: 7 m × 5 m = 35 m²
Same area, different perimeter
Rectangles can cover the same space in different shapes
3 × 8 rectangleArea = 24 units²
Perimeter = 22 units
Perimeter = 22 units
4 × 6 rectangleArea = 24 units²
Perimeter = 20 units
Perimeter = 20 units