What is the missing length of a rectangular prism where the height and width are both 9 cm and the surface area is 432 cm2 ?(1 point)

1 answer

To find the missing length of the rectangular prism, we first need to find the total surface area of the prism.

The formula for the total surface area of a rectangular prism is:

Surface Area = 2lw + 2lh + 2wh

Given that the height (h) and width (w) are both 9 cm, we can substitute these values into the formula:

432 = 2l(9) + 2(9)(9) + 2(9)l
432 = 18l + 162 + 18l
432 = 36l + 162
36l = 270
l = 7.5

Therefore, the missing length of the rectangular prism is 7.5 cm.