The square has length . Its perimeter, which is the amount of wire used to make the square, must therefore be .

The remaining amount of wire,cm(not ), is used to make the circumference of the circle ().

You now know the radius of the circle and the side length of the square, so you can find the area of both shapes now.

When you find , notice that the required expression is , so the hint is that you should leave the expression as is without expanding the term in the square or combining fractions.

You can take out the constant in the second term's denominator and differentiate using the chain rule, which will give you the required answer.

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