Calculate Square Side Length: Finding x When Area = 144

To calculate the length of the sides of a square given that its area is 144, we follow these steps:

• The problem gives us that the area of the square is 144. We are looking for the side length ($s$) of the square.
• We use the formula for the area of a square: $\text{Area} = \text{side}^2$. Substituting the given area, we have $144 = s^2$.
• We solve for $s$ by taking the square root of both sides: $s = \sqrt{144}$.
• Calculating $\sqrt{144}$, we find that $s = 12$.

Therefore, the length of the sides of the square is 12.

This corresponds to choice 4: $\sqrt{144}$, which emphasizes using the square root operation. However, the final calculation confirms that $s = 12$.