Let ABC be a triangle which sides are of unequal length请问下这句中of用法的解释.我看了半天也不懂为什么要加个of,是whose不是which，打错了

Let ABC be a triangle which sides are of unequal length请问下这句中of用法的解释.我看了半天也不懂为什么要加个of,是whose不是which，打错了
Let ABC be a triangle which sides are of unequal length
请问下这句中of用法的解释.我看了半天也不懂为什么要加个of,
是whose不是which，打错了

Let ABC be a triangle which sides are of unequal length请问下这句中of用法的解释.我看了半天也不懂为什么要加个of,是whose不是which，打错了
of表示...的意思,比如说of importance就等于important,of unequal length的意思就是三边的长度是不同的