Describe an example where materials are prepared as fluids so that they can be moved easily

In general solids are easier to transport than liquids, but the above metal example is a valid one and the only other one that comes to mind is that of concrete. It is mixed as a liquid and transported as such, but then sprayed or laid down to dry and form a solid surface or filler. 

Explanation:

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray