The answer is cos70
the angles add up to 180, so 180 - 90 - 20 = 70 degrees.
so, let's say the length is "L".
width = 2 shorter than L = L - 2.
height = 9 more than twice L = 2L + 9.
check the picture below.
keeping in mind that the volume of a rectangular prism is simply the product of its length, width and height, and since we know the volume has to be 45.
from those 3 factors, we get those solutions/zeros.
we can't use -5/2, or -3, because the length can't be a negative value, so L = 3.
that means the width = 3 + 2, and the height = 2(3) +9.
18.6 cm2
B
21.9 cm2
C
61.5 cm2
D
65.5 cm2