The W930 tries to work vertically and horizontally (see corresponding videos on the net). Therefore, the result will probably not be very convincing if the window sides are not horizontal or vertical. The robot will then leave "saw teeth" on the edge. However, I myself only have rectangular windows, usually over 5m2.
In my opinion, the purchase is only worthwhile for larger rectangular window areas and/or for external areas that are otherwise inaccessible or only accessible with ladders.

Provided the trapezoid has a greater width at the top than the side length of the W930.
Greetings
Andre