I am currently experimenting with welds and weld constraints and trying to add CFrame.Angles with a CFrame and get the following error message:

`workspace.Model.Tween.CFrame = workspace.Model.Tween.CFrame + CFrame.Angles(0, math.rad(90), 0):1: invalid argument #2 (Vector3 expected, got CFrame)`

I have found that multiplication has exactly the effect I want, but have no idea why this works! Can someone give me a simple explanation?

Fixed code:

```
workspace.Model.Tween.CFrame = workspace.Model.Tween.CFrame * CFrame.Angles(0, math.rad(90), 0)
```