A wire of length 30 m is cut into two pieces. One of the pieces is folded into a square and the other into a circle. If 'x' m is the length of one of the pieces, the combined area of the square and the circle is given by: |
$\frac{x^2}{4 \pi}+\frac{1}{4}(30-x)^2$ $\frac{x^2}{4 \pi}+\frac{1}{16}(30-x)^2$ $\frac{(30-x)^2}{4 \pi}+\frac{x^2}{8}$ $\frac{(30-x)^2}{16 \pi}+\frac{x^2}{4}$ |
$\frac{x^2}{4 \pi}+\frac{1}{16}(30-x)^2$ |
The correct answer is Option (2) → $\frac{x^2}{4 \pi}+\frac{1}{16}(30-x)^2$ $\text{Let } x \text{ be the length used for the circle, then } (30 - x) \text{ for the square}$ $2\pi r = x$ $r = \frac{x}{2\pi}$ $\text{Area of circle} = \pi \left(\frac{x}{2\pi}\right)^2 = \frac{x^2}{4\pi}$ $\text{Side of square} = \frac{30 - x}{4}$ $\text{Area of square} = \left(\frac{30 - x}{4}\right)^2 = \frac{(30 - x)^2}{16}$ $\text{Total area} = \frac{x^2}{4\pi} + \frac{(30 - x)^2}{16}$ The combined area is $\frac{x^2}{4\pi} + \frac{(30 - x)^2}{16}$. |