Difficulty in taking the slice at a specified angle of 78 degree in clockwise direction from vertical axis

Hello Experts,
I wanted to take a slice at angle of 78 degree from vertical axis (y-axis). I am confused regarding the convention used in the Paraview. For example: if I put the slice normal as : 1, 0, 0 then it’s clear that it will slice along y axis. But if I used a slice normal as: 1, -1, 0 then it’s a slice at an angle of 45 (I assume) in clockwise direction. But if I used a slice normal as: 1, -45, 0 then it’s a slice at an angle of 0 (I assume) from the vertical axis. By doing all this exercise I am really confused, what is the convention that is followed by taking a slice direction (specified as “Normal” in Paraview). Sorry for asking naive and so confusing question, I have attached the screenshots of all the 3 cases herewith. Any comment/suggestion will be a great help. Thanks in advance.

a Nornal is a normalized vector orthogonal to the plane: