Depending on the size, they are all just granny squares that are attached to form shorts. You can see the schematics of the different sizes that are available in the free pattern.
The granny square is a unique one, it's not just the typical square and the pop of colour in the centre is sweet.
I would highly recommend the invisible join for these. You could add more squares if you want the shorts to be longer as well. Just see the schematics to figure out how many additional squares you would like to do for the length.
Are you looking for more summer-wear? We have a collection of summer gear in crochet for you to consider. This is the 25 Summer Tops and Overlays.