The cross-section of a 10 meter wide one-way road sits on the x-axis (x= 0 corresponds to the center of the road while x=−5 is the left shoulder and x= 5 is the right shoulder).  The height of a bridge going over the road is given by 4 cos(π/10) + 1.  I would like to build a rectangular prism shaped truck that is 6 meter long and has the largest volume possible.  Without using your calculator, find and describe as well as possible the optimal width and height of the truck.