Solve the Problem $256 \mathrm {~cm} ^ { 2 }$ Let

Multiple Choice

Solve the problem.
-Consider all rectangles with an area of $256 \mathrm {~cm} ^ { 2 }$ . Let $x$ be the length of one side of such a rectangle. Express the perimeter as a function of $x$ and determine the dimensions of the rectangle that has the least perimeter.

A) $\mathrm { P } ( \mathrm { x } ) = 2 \mathrm { x } + \frac { 512 } { \mathrm { x } } ; 4 \mathrm {~cm} \times 64 \mathrm {~cm}$
B) $\mathrm { P } ( \mathrm { x } ) = \mathrm { x } + \frac { 256 } { \mathrm { x } } ; 16 \mathrm {~cm} \times 16 \mathrm {~cm}$
C) $\mathrm { P } ( \mathrm { x } ) = 256 \mathrm { x } ; 8 \mathrm {~cm} \times 32 \mathrm {~cm}$
D) $\mathrm { P } ( \mathrm { x } ) = 2 \mathrm { x } + \frac { 512 } { \mathrm { x } } ; 16 \mathrm {~cm} \times 16 \mathrm {~cm}$