Slabs comprise the maximum area of the building which comes up to 20 to 25 percent of total cost. Thus the economical design of the building can be achieved to great extent by designing the slab economically. The yield line method is a method which allows the redistribution of force that will take place after the yielding of slab reinforcement. Using this method, slabs that are easy and quick to design and to construct can be generated. The resulting slab is thin and has the very low amount of reinforcement in regular arrangements. This makes it easy to detail. Above all, this design generates concrete slab which is very economical, because features at the ultimate limit state are considered. The aim of this study is to apply the yield line theory for polygonal slab of N equal sides by using the virtual work principle and obtain a general relationship between the ultimate load and desired arrangement of reinforcement in a slab for any given radius of circle in which the slab is inscribed and to generate nomograms for frequently used slabs.