Answer: 
Step-by-step explanation:
The slope of the line is

Using the point (-2, 0) to substitute into point-slope form, we get the equation to be 
Answer:
-2.66666666667
or just
-2.67
Step-by-step explanation:
The concept useful in finding the answer to this item is ratio and proportion, the ratio of the height of your friend with the shadow casted should be proportional to the height of the rock with the length of the shadow it cast. That is,
5.5 ft / 18 ft = x ft/ 209.5 ft
The value of x from the equation above is 64 ft.
The answer to this is -8/3