Which best describes the relationship between Line 1 and Line 2? Line 1 passes through (-3, 6) and (-7, 11)
Line 2 passes through (1, 8) and (-4, 4)
A. perpendicular
B. They are the same line.
C. parallel
D. neither perpendicular nor parallel

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4