Area is an important concept in physics, engineering, science and everyday life. Area determines how much solar energy can be collected from a solar panel, how much grain can be grown in a plot of land, and how much paint you need to cover a wall. Calculating area can be complicated for some shapes, but they are measured in square feet, square meters or square miles because the area of a square is the most basic of all to calculate.

### Step 1

Find the length of the first side of your square or rectangle in linear units, and call this length X.

### Step 2

Find the length of a side adjacent and perpendicular to the first side, and call this length Y. If you know your shape is a square, you can just set Y equal to X.

### Step 3

Multiply X by Y to get the area of the rectangle in square units. So if the length of one side (X) is 6 inches, and the other side (Y) is 7 inches, then the area of the rectangle is 42 square inches.