Given two points
, the slope of the line passing through the two points is

So, in your case, you have

(-6,-4)
If you dilate a point, (c,d) about (a,b) by a scale factor by k. You'll going to subtract each coordinates where the point will be dilated about (a,b) from the point (c,d) and then multiply them by k. This would be the formula if you want: (k(c -a), k(b -d))
Let's say F is the dilation of D about the origin or (0,0) then the x coordinate of F would be

This would be the y coordinate of F:

Thus the coordinates of F is (-6,-4)
Answer: Yes, well done.
Step-by-step explanation:

This is a 30-60-90 triangle
opposite side of rigt angle=2x
opposite side of 60 degrees is x√3
opposite sides of 30 degree is x
the right angle is at the base of the building so therefor
200=x
2x=distance from surveor to top of building and x√3=height of building
x=200
200√3≈346.41
the answer is 346.41 feet