For example , if the side surface of a cylinder ( or any prism ) is cut lengthwise , the surface can be flattened out into a rectangle .
Most basic formulas for surface area can be obtained by cutting surfaces and flattening them out .
If the side surface of a cylinder ( or any prism ) is cut lengthwise , the surface can be flattened out into a rectangle .
Most basic formulas for surface area can be obtained by cutting surfaces and flattening them out .