If there are 5 flats in a key signature, what are the flats? What Major key signature has 5 flats and what trick can you use to figure this out?

To create an illustration of perspective, this artist did all of the following except 1) show clear orthogonal lines 2) have an implied vanishing point 3) distort proportion to keep the background and foreground the same size 4) include value changes between the foreground and background i was thinking maybe 1