Both the right and left angles are the same and since the left angle is 35 degrees we can safely conclude the right angle is as well, so all you have to do is is both of the 35 degree angles together which gives you 70, then subtract it from 180. 180-70=110 so that is the angle of 1. and since the bottom and top are the same the angle of 4 is also 110
There are 5 blades, equally spaced. So the angle between adjacent blades is 360° / 5 = 72°. So you can rotate the fan 72° and the blades will align again.
