14（a*2+b*2+c*2）=(a+2b+3c)*2
14a*2+14b*2+14c*2 = a*2+4b*2+9c*2+6ac+12bc
13a*2+10b*2+5c*2-4ab-6ac-12bc = 0
(2a-b)*2+(3a-c)*2+(3b-2c)*2 = 0
因为(2a-b)*2,(3a-c)*2,(3b-2c)*2大于等于0,相加等于0
所以2a-b=0 3a-c=0 3b-2c=0
解得 a:b:c = 1:2:3
柱:*2为平方