Question

the area of a square painting is 81 cm². what is the length of one side? options: -9, 40.5, 9, (partially visible option)

Explanation:

Step1: Recall the formula for the area of a square

The area \( A \) of a square with side length \( s \) is given by the formula \( A = s^2 \).

Step2: Solve for the side length

We know that the area \( A = 81 \, \text{cm}^2 \). So we need to find \( s \) such that \( s^2 = 81 \). Taking the square root of both sides, we get \( s=\sqrt{81} \). Since the length of a side cannot be negative (as it represents a physical length), we take the positive square root. \( \sqrt{81} = 9 \).

Answer:

The length of one side is \( 9 \, \text{cm} \), so the correct option is the one with \( 9 \) (assuming the orange box is labeled with \( 9 \), e.g., if the options are as shown: the orange box with \( 9 \) is the answer, so in the format for multiple - choice, if the orange box is option C (for example), it would be C. 9. But from the visual, the orange box has 9, so the answer is 9 (and if we consider the options, the one with 9 is the correct choice).