120, 90, 30 if you're going from the depths of the water to water level
The answer would be the first choice. 
Explanation: The reason for this is that the question was pretty much just asking what the area of the resulting two-dimensional cross section would be -the shape in gray- (which can be found by using the formula
. To add on, since the dimensions of the shape are already given (5 and 3) all you've to do is multiply: 3*5=15
That's how you get to the answer.
I think it would be 36 it’s what my friend told me I’m not sure though sorry if it’s wrong.
Answer is 2263.
Checkpoint 1 is -86
Checkpoint 4 is 2177
Subtract -86 from 2177....2177-(-86)
=2263
2263 is how much higher checkpoint 1 (-86) is from checkpoint 4 (2177)
Hope this helps! :)
The lateral area of the prism is given by:
LA=[area of the two triangles]+[area of the lateral rectangles]
hypotenuse of the triangle will be given by Pythagorean:
c^2=a^2+b^2
c^2=6^2+4^2
c^2=52
c=sqrt52
c=7.211'
thus the lateral area will be:
L.A=2[1/2*4*6]+[6*8]+[8*7.211]
L.A=24+48+57.69
L.A=129.69 in^2
The total are will be given by:
T.A=L.A+base area
base area=length*width
=4*8
=32 in^2
thus;
T.A=32+129.69
T.A=161.69 in^2