math
posted by dianalish` on .
what is the surface area of a rectangular prism with the width 4cm lenth 5cm height of 3cm

There are 6 surface areas, but we need
to calculate only 3 because:
The Front and Back are equal.
The Left and Right are equal.
The Top and Bottom are equal.
So we multiply each calculation by 2:
As = 2(4*3) + 2(5*3) + 2(4*5),
As = 24 + 30 + 40 = 94cm^2.
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