I think the question ur asking is what’s the volume of water?? If so then the volume of water is 1L
X^2+ (y+8)^2 = 81.....this is C.
X^2 + y^2 + 16y +64=81 so x^2 + y^2 + 16y = 17.....this is D.
So I’d say C and D are correct
D. 54° as you know an external angle has to equal up to 360
when you start plugging in 360 by 36 gives you 10
360 by 40 gives you 9
360 by 45 gives you 8
360 by 54 gives you 6.666 repeating you know that it isn't possible
you cannot have a repeating number of sides as an angle measure
that's how you get that answer
10,800 milligrams equals 10.8 grams so that the first highlighter has the greater mass