The ratio of the height and width remain constant as you change it's size.
So..
A = Old width
B = Old height
C = New width
D = New height
A/B = C/D
Plug in the values we have
42.9 / 32.5 = 3.3 / D
Multiple both sides by D
D * 42.9 / 32.5 = 3.3
Multiple both sides by 32.5
D * 42.9 = 3.3 * 32.5
Now divide both sides by 42.9
D = 3.3 * 32.5 / 42.9
Now simply do the multiplication and division using the available numbers.
D = 2.5
