Question
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)
To find the missing length of the rectangular prism, we first need to calculate the surface area of the rectangular prism using the formula:
Surface Area = 2lw + 2lh + 2wh
Given that the height and width are both 9 cm, we have:
Surface Area = 2(9)(l) + 2(9)(9) + 2(l)(9)
Surface Area = 18l + 162 + 18l
Surface Area = 36l + 162
Given that the surface area is 432 cm^2:
432 = 36l + 162
36l = 432 - 162
36l = 270
l = 270 / 36
l = 7.5 cm
Therefore, the missing length of the rectangular prism is 7.5 cm.