The way this comment was going I was pleasantly surprised to see that the iPhone Duo adhered to the ISO standard.
From Apple's diagonal measurements [1], it looks like the screen is actually a few mm off from the closest ISO 216 sizes.
d = 7.58in = 192.532mm [1]
d^2 = w^2+h^2
Unfolded:
h = d/sqrt(3) = ~111.1584mm
w = h*sqrt(2) = ~157.2017mm
Closest ISO 216 size: A6 (105x148)
Folded:
D = 5.36in = 136.114mm [1]
H = D/sqrt(3) = ~78.5855mm
W = H*sqrt(2) = ~111.1366mm
Closest ISO 216 size: A7 (74x105)
[1] https://www.apple.com/iphone-duo/specs/
alt Hacker News
From Apple's diagonal measurements [1], it looks like the screen is actually a few mm off from the closest ISO 216 sizes.
d = 7.58in = 192.532mm [1]
d^2 = w^2+h^2
Unfolded:
h = d/sqrt(3) = ~111.1584mm
w = h*sqrt(2) = ~157.2017mm
Closest ISO 216 size: A6 (105x148)
Folded:
D = 5.36in = 136.114mm [1]
H = D/sqrt(3) = ~78.5855mm
W = H*sqrt(2) = ~111.1366mm
Closest ISO 216 size: A7 (74x105)
[1] https://www.apple.com/iphone-duo/specs/