What is the surface area of a rectangular prism with a width of 15; length of 10; and height of 8.

To find the smaller side of a rectangular prism on each end you must multiply the width and height:

15*8=120

Then you must times this by 2 because we have 2 of those sides (one on each end):

120*2=240

Then find the rectangular shape's surface area by multiplying the length and the height:

10*8=80

You must then multiply this by 4 as there are four of those sides:

80*4=320

Then add the two answers together to find the total surface area:

320+240=560

L = length = 10
w = width = 15
h = height = 8

S = 2 [ lw + lh + hw ]

plugging in the values ...

S = 2 [(10)(15) + (10)(8) + (8)(15)]
S = 2 [150 + 80 + 120]
S = 2 [350]
S = 700

Then why is the question on here if you know the answer