You can see it easily. You get down beside your pedal and press it down with your hand. Then you look at the beater shaft. If it's straight up and down, it's 90 degrees. I'm not using a protractor. These new Yamahas have a pretty big beater 'head', so they will make contact right around 90 degrees (perpendicular to the floor).
That's an optical illusion. The beater does not rotate around the beater holder but around the drive shaft. The angle of the beater shaft is not relevant. Draw a line from the center of the beater head to the drive shaft and you have the real angle.