How do I know if this is loose skin or fat?

I'm 18 and I've recently lost 50 pounds , I still have about 20 to go and my upper arms are hanging , my lower abdomen and inner thighs as well but I don't know if its loose skin or fat , how do I tell the difference ? like can this be hanging fat since I'm still overweight

I lost the weight in a healthy way , I ate healthy , added cardio and strength/ weight training , lost it in an entire year so I took my time . is there a way to know if its fat like by pinching or something , I hope its fat because I can't afford surgery
How do I know if this is loose skin or fat?
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