He's described as around thirty years old, six feet tall and of medium build.

他被描述为大约三十岁，身高6英尺，体格中等。

《柯林斯英汉双解大词典》

He is neither tall nor short. He is medium height.

他不高也不矮，中等个儿。

youdao

Web sites are a vertical medium, but your monitor (probably) isn't as tall as everything you might want to capture from a site.

一般网页通常大小适中，但是你的显示器(或许)不够大无法完整显示你想要截取的所有内容。

youdao

Mrs Cameron is described as 5ft 3in (1.6m) tall, of medium build, with short-bobbed blonde hair.

BBC: Police concern for missing woman Meryl Cameron

The man is described as white, about 6ft tall, of medium build and in his early to mid 30s.

BBC: Thief in Guildford takes phones worth ?17,000

He is described as 5ft 10in tall, of medium build, with blue-grey eyes.

BBC: Owain Roberts