if in night my 7 year old kid sleep 6 hrs and take 3 hrs nap in afternoon. is this schedule good for his physical and mental health?

A. Obviously not as a minimum sleep at this age a child should take during the night time is about eight hours minimum I am talking about so should be at least eight hours in the night and if your child is sleeping even for one or two hours during the daytime it’s good enough because when we talk about night sleep is it mandatory for everyone to have a minimum sleep of eight hours and for kids it is rather more important than adults