help me solve pleaseMarla walks straight from the parking lot to the lake as shown, where the sign reads that she is 320 m from the dock. How far is Marla from the parking lot?

As you can see in the given figure,
The parking lot is at point C and Maria is at point D
We are asked to find the length CD (marked x)
As you can see there are two triangles.
Triangle △ADC and △BDC
The length of side AD is given by
[tex]\bar{AD}=500-320=180[/tex]Now we can apply the property of similar triangles, if the triangles are similar then the ratio of corresponding sides will be equal
[tex]\begin{gathered} \frac{BD}{CD}=\frac{CD}{AD} \\ \frac{320}{x}=\frac{x}{180} \end{gathered}[/tex]Let us solve for x
[tex]\begin{gathered} \frac{320}{x}=\frac{x}{180} \\ x\cdot x=320\cdot180 \\ x^2=57600 \\ x=\sqrt[]{57600} \\ x=240\: m \end{gathered}[/tex]Therefore, Maria is 240 m away from the parking lot.