Calculate the Area of a Square: Finding Square Units for 40-Unit Side Length

Area measures surface space, not distance around the edge. When you have a 40×40 square, you're filling 1600 individual unit squares inside it. Doubling only gives you the perimeter!

Perimeter = walking around the square (add all sides)
Area = filling inside the square (multiply length × width, which equals $L^2$ for squares)

Yes! Area grows exponentially with side length. A 10-unit square has area 100, but a 40-unit square has area 1600 - that's 16 times bigger because $40 = 4 \times 10$ and $4^2 = 16$!

Always use square units for area! Since the side is 40 units, the area is 1600 square units. The word 'square' tells us we're measuring area, not length.

For rectangles, use $A = length \times width$. Squares are special rectangles where length equals width, so $A = L \times L = L^2$.