steps to design triangular patch antennas

can anyone please tell me how to design triangular patch antennas. also why we can say triangular antenna is better tah rectangular anr circular

Sir Using triangular patch we can obtain circular polarisation with just 1 feed whereas in case of rectangle & other we require two quadrature phase shift causing feeds.

you can find all things about designing the microstrip antenna with arbitrary shaped in MICROSTRIP ANTENNA DESIGN HANDBOOK by Ramesh Garg, Bhartia, Bahl.
It is a very useful book.