What is the equation of this trend line? Please help ASAP!

Can (3,5 and square root 34) be sides on a right triangle?

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Quadrilateral abcd in the figure below represents a scaled-down model of a walkway around a historic site. quadrilateral efgh represents the actual walkway. abcd is similar to efgh. what is the total length, in feet of the actual walkway?