x=2y is linear and can also be writtend as y=x/2
The x-intercept is when y=0, so we plug that in our equation,

. +12 on both sides to get

. Divide by -8 to get
The fourth side = f, now let's solve for f
value of fourth side = f = 96 km
-19/40.
This can be found using the slope formula.