Question

what is the missing length? area = 9 km² c = kilometers

Explanation:

Step1: Recall area formula for square

The area formula for a square is $A = c^2$, where $A$ is the area and $c$ is the side - length.

Step2: Solve for $c$

Given $A = 9\ km^2$, we have $c^2=9$. Taking the square root of both sides, $c=\sqrt{9}$. Since $c$ represents a length and cannot be negative, $c = 3\ km$.

Answer:

3