>>41413649
It's kind of hard to explain without visuals. Imagine a flat plane on your skin where you're going to inject, say 1/2 an inch by 1/2 an inch with the injection site in the middle. Relative to that plane, you should inject at a 90 degree angle. If you inject in the vastus lateralis, the needle would be a bit tilted compared to the ground, but it shouldn't be at an angle relative to the patch of skin you're injecting into