Design-wise, convex awnings start as a “perfect radius”, ie the height and projection are the same. For example, a 3′ tall awning would be a 3′ projection or a perfect quarter circle. However, if space or need dictates, a convex awning can just as easily be made an “imperfect radius”. For example 2′ tall and 3′ projection.
They may have flat ends or curved and rounded ends , also known as a “long dome”.