I believe the answer your looking for is B.. good luck my friend!
We have to calculate the suface of the four walls and the ceiling.
Surface of the four walls=2(10 ft * 10ft ) + 2(12 ft * 10 ft)=200 ft² + 240 ft²=
=440 ft²
Surface of the ceiling=10 ft * 12 ft=120 ft²
Total surface=440 ft² + 120 ft²=560 ft²
Now, we have to caluclate the number of gallons of paint.
1 gallon------------------------400 ft²
x----------------------------------560 ft²
x=(1 gallon * 560 ft²) / 400 ft²=1.4 gallons.
answer: Ryan need to paint all four walls and the ceiling 1.4 gallons.
The midpoint is just the average of the coordinates of the endpoints.
((-8+2)/2, (-3-5)/2)
(-6/2, -8/2)
(-3,-4)