- Find, in terms of , the radius of the circle into which one of these wires can be bent, using circumference of circle =
- Find the length of one of the four equal lengths, by subtracting from and dividing the result by . This gives the height of the cylinder in terms of .
- Use the formula for the volume of a cylinder to write down an expression for the volume, , in terms of .
- Use to find the value of which makes the value of a maximum or minimum.
- Check that this value gives a maximum.
Hope you can do it from here.