And in this because the the cambered aerofoil, so called aerofoil section is more complex in nature. So, but it is quite interesting to see that by through suitable transformation, again we are able to of the suitable arrangement of the Joukowski transformation from a circle, we can map s to n aerofoil section. We will consider two cases, today we will emphasize on a symmetric aerofoil section, and next we will discuss about the cambered aerofoil. So, this let us see what exactly, I mean a aerofoil.