So I’m trying to shoot these kunais in star formation like this
I just got the circle with star image on it and changed its coordinates to 0,0,0. I placed kunais on edges and got their PrimaryPart position. After that I just did this

It worked but only when I was shooting kunais directly to top or bot. Any time I changed angle they would mess up. Well that’s because as you can see in image Y coordinate always stays the same and I need to change it based on angle but I have no idea how.
Here’s a gif to get the better idea of what I’m talking about: https://gyazo.com/4ef73d2ae77b0e2fd0e54db0aeceb8a4

For example if camera will be directly on top of my char. it will look like this. This way it’s easy, but if camera isn’t on top of my char triangle type changes. I guess if I can get distance between camera and my mouse. I’ll know all triangle sides and after that I’ll be able to calculate angles as well. I just need to look up mathematical formulas for that.

You only need to know two sides of a right triangle to be able to solve everything else. In your case, use tangent (tan(angle) = opposite/adjacent) to find the angle.