Original formula > = (A 2+B 2+C 2)/(A+B+C)
According to:
Available: a 2+b 2+c 2 > = (a+b+c) 2/3
So: original type >; =(a^2+b^2+c^2)/(a+b+c)>; =(a+b+c)/3
High school math and physical education teachers can only earn one third ... hehe.