16 ft
Explanation
Step 1
because the ligth comes in the same angle, we have 2 similar triangles .
so,as the triangles are similar,the ratio of the shorter leg to the bigger leg must be equal.

Step 2
solve for h

therefore, the heigth of the tree is 16 ft
The equation of a line is defined by: y=mx+b
Step 1: Find the slope (rise over run) so, the rise is 15.7 and the run is 6. 15.7/6=2.62
y=2.62x+b
Step 2: Find the b value (y intercept) - this is where the line goes through the y axis. In this case, it's 15.7
Step 3: add the slope and the b value together - y=2.62x+15.7
Answer:
You might want to put that in a picture, because that makes very little sense.