题目内容：

三条横线在数学上是什么符号?

优质解答

≡ is equivalent to 恒等于或同余
　以之参照的符号
＝ is equal to 等于号　　≠ is not equal to 不等于号　　≌ is approximately equal to 全等于号　　≈ is approximately equal to 约等于号