As we can see in the shown figure:
1) I and J are parallel
2) I and g are perpendicular because we have constructed the steps to make the perpendicular to the line I
3) J and g are perpendiculars because I and J are parallel and I perpendiculars to g
since the graph has direct variation as data in x axis increases y also increases.
so we need to find how many miles travelled per galloon .
we distance travelled per gallon =total distance travelled/galoons of fuel used.

for part b) slope=rise/run



slope of the graph is 2
-3x4.5=13.5. 4.5x0.5=2.25
-13.50
+2.25
_____
15.75 pints
MP
PM
Assuming your n is on a side