If you're just playing around for fun, set the hoop at whatever height you want. When played as a sport though, the hoop is virtually always set at 10 feet. Though some youth leagues for kids under 10 years put the hoop at 8.5 feet, I'd recommend playing or practicing with it at 10 feet, so that you'll learn skills applicable to school Basketball, and you won't have to readjust your technique later on.
3.5 meters
you should get him a jersey or hanging basketball hoop for his door.
54 inches
About '56'
The average height of a nine year old child is 47-49 inches (3ft11-4ft1)
5'9"
The average height of Australian men was 175 centimeters or five feet nine inches tall. Women are somewhat shorter on average.
The average Height of a 9 year old is 49 inches (1.2m) and the average weight is 61.6lbs (4.3 stone)
I don't know but I am nine and I am 5 ft 2 and about 119.4
i think about 85 pounds
The height of nine year old girls ranges from 48 to 57 inches but the average is about 52 and a half inches
Approx. 4"5-4"7