what is the missing length of a rectangular prism where the height and width are both 9 cm and the surface area is 432cm squared?

Answer 1

To find the missing length of the rectangular prism, we can use the formula for the surface area of a rectangular prism:

Surface Area = 2lw + 2lh + 2wh

Given that the height and width are both 9 cm, we can substitute these values into the equation:

432 = 2l(9) + 2(9)h + 2(9)h
432 = 18l + 36h

Since the height and width are equal, we can simplify the equation further:

432 = 18l + 72

Now, we can isolate the length (l) by subtracting 72 from both sides and then dividing by 18:

360 = 18l
l = 20

Therefore, the missing length of the rectangular prism is 20 cm.