To add or not to add adjective after 一樣。 I was browsing juuku and I found the sentences:


  李明的年龄和王林的年龄一样。


and


  萨莉：“他们年龄一样大吗？”


From this I assumed that, when the quantity of comparison (年齡）has been fixed, I am free to choose whether or not to add the corresponding adjective （大） after 一樣。

But when I presented the following sentences to native speakers, there was no agreement, as to whether the 高 was superfluous or not：


  我跟他身高一样高 / 我身高跟他一样高。


Can you enlighten me, preferably citing from some book?
Yes, 高 is superfluous. There is no need to say two 高 in a sentence.

I'd rather say 我跟他一樣高. Although you can also say 我跟他身高一樣, the former one is a little bit shorter.

If you say 我跟他一樣大, one might not know what kind of '大' it is. In this case, one might add 年齡 to the sentence. But if the context is known in conversation, it is no need to add 年齡 to the sentence.