How to Find Surface Area of a 3D Shape
3D objects can sometimes intimidate us in math, especially when given to us in a word problem, but don’t fear, they break down into steps very nicely.
Lets try one together. Right, so what do we know? Well, we know that we need the surface area of a 3D object is the sum of the surface area of its six sides. In our problem, we know we have a height of 4 a width of 20 and a length of 32.
We have a total of six sides, so lets figure out what those areas will be.
Ends: height times width times two
Short sides: height times length times two
Big sides: length times width times two
Or, more simply
So let’s figure out our actual area now.
h*w*2 = 4*20*2 = 160
h*l*2 = 4*32*2 = 256
l*w*2 = 32*20*2 = 1280
We add the sums of all those sides together to get our total surface area.
160 + 256 + 1280 = 1696 = Total SA
I hope that helps. Thanks for watching this video lesson, and until next time, happy studying.