Mathematical approach for feedline design

I want to feed rectangular patch antenna using a microstrip feedline (50 ohm)
What is the approach taken ?

Are these the 2ways of using a microstrip feedline -
1. Inset feed ==> we find the location on the patch such that its impedance at that point is 50 ohms. And then we use the inset feed (50 ohms directly) as then there will not be any impedance mismatching.

2. Edge fed ==> We find the impedance at the edge of the patch. And then design a transformer (lamda/4) so that we can get a proper matching to the feedline which is 50 ohms.

3. Edge fed ==> We dont design any transformer. And directly use the 50 ohm feedline. What is its drawback ?

Are these 2 approach correct ?