How to actually grind angles 15°, 30° and 45°

[shopandmath]

How to actually grind angles 15°, 30° and 45°
In this video I'm going to demonstrate how to set up to grind 15° 30° and 45° on angled parallels
in this setup I will be using two different methods for the 45° and 30° I will be using a sine bar and angle plate
on the 15° I will be using a vice and a sine bar because the angle is extremely small and would be very difficult to clamp using a sign plate
I will also demonstrate how to calculate 15° 30° and 45° setups using a 5 inch sine bar and Gage blocks