Area = length × width
Perimeter = 2 × (length + width)
For a square, Area = side × side
For a square, Perimeter = 4 × side
For a triangle, Area = 1/2 × base × height
For a triangle, Perimeter = sum of all sides
For a circle, Area = π × radius²
For a circle, Perimeter = 2 × π × radius
Use the correct units for area
Use the same unit for all sides when finding perimeter