Geometry
Perimeter and Area of a Square
Boundary versus surface: 4a and a²
- Primary school
- about 3 min
- 4 of 9 in the family
Not started
Side of the squarea = 3 cm
perimeterP = 4 · 3 = 12 cm
areaA = 3 · 3 = 9 cm²
The boundary has 12 segments 1 cm long; inside there are 9 squares of 1 cm².
| a | P (cm) | A (cm²) |
|---|---|---|
| 1 | 4 | 1 |
| 2 | 8 | 4 |
| 3 | 12 | 9 |
| 4 | 16 | 16 ⚑ |
| 5 | 20 | 25 |
| 6 | 24 | 36 |
| 7 | 28 | 49 |
| 8 | 32 | 64 |
The perimeter grows with the side, the area with its square. At a = 4 (⚑) both are 16 - the same number, but centimetres are not square centimetres.