Plot a graph of y-axis against x-axis.
The graph should be a straight line passing through:
(-2,0.8) , (-1,-0.4) , (0,0) , (1,0.4) and (2,0.8)
-4.2 degrees. What you would do is from 8-12 (midnight) is 4 hours. So it dropped -16.8 degrees in those 4 hours so -16.8 / 4 is -4.2 degrees. So it dropped -4.2 degrees every hour but it was also -4.2 degrees at 9:00 p.m.
M is the centroid and the centroid divide the line in 1:2 ratio . So M divide BQ in 1:2 ratio and the total length of BQ is 18.
Therefore BM is one third of 18 . ANd one third of 18=6
So BM =6 and MQ=12 .
The area of the base is:
A = root ((s-a) * (s-b) * (s-c) * (s))
Where,
a, b, c: sides of the triangle
s = (a + b + c) / 2
We have then:
s = (9 + 9 + 9) / 2
s = 13.5
A = root ((13.5-9) * (13.5-9) * (13.5-9) * (13.5))
A = 35.07
Then, the surface area of the prism is:
S.A = 2 * A + 9h + 9h + 9h
Where,
h: height of the prism:
Substituting values:
421.2 = 2 * (35.07) + 9h + 9h + 9h
Clearing h:
27h = (421.2 - 2 * (35.07))
h = (421.2 - 2 * (35.07)) / (27)
h = 13
Answer:
the height of the box is:
h = 13 inches
