The triangle symbol is easy enough to make on paper, as it only consists of three lines, but it’s also simple to create on the computer, thanks to the “Alt” key and number pad. Almost all word processing programs support the use of Alt codes, but some websites, such as forums and instant messengers, do not. You must use a keyboard that has a number pad to insert the triangle symbol.
Hold down one of the “Alt” buttons on your keyboard with your left index finger.
Press “30” to insert a vertical triangle facing up. Press “31” to insert a vertical triangle facing down, “16” to insert a triangle facing left or “17” to insert a triangle facing right. You must hold the “Alt” button while you press the numbers.
Release each key on the keyboard to make the triangle symbol appear.