设三边长为a,b,c,则
ab=根号3
bc=根号2
ac=根号6
a/c = 根号(3/2)
c^2根号(3/2)=根号6
c = 根号2
a = 根号6/根号2 = 根号3
b = 根号2/根号2 = 1
长方体的对角线长
= 根号(a^2+b^2+c^2)
= 根号(3+1+2)
= 根号6