I have a creative math assignment which my class was tasked to do. Thus I decided to create my work on physics, more specifically aerodynamics. I want to create a function which calculates Drag with respect to the angle formed between the upper body of a cyclist and the seat. Thus, with a known velocity (i.e. 30 km/h), air density (i.e. 1.000 kg/m^3), and drag coefficient, the frontal area would be the only unkown. Here is where I want to model an equation for frontal area given the angle between the cyclist's back and the seat (which is parrallel to the floor), other measurements such as height, torso width, etc, would be determined experimentally. My question is, what factors (related to body posture) should I take into consideration when calculating the Drag of a cyclist? How should I calculate the frontal area of the cyclist?