剑桥词典a three-sided area on the inner surface of the bladder (= the bag where urine collects ) （膀胱內壁的）三角區 Since most of these tumours involve the trigone, they are rarely operable . 這些腫瘤大部分發生在膀胱內壁三角區，因此極少能做手術。 返回 trigone