How to create a triangle in photoshop?

Question

Adobe Photoshop

I'm a beginner how to cut like this

Answer 1

This rectangle is flipped. Triangles did not see what would be created

Answer 2

God, why is Google no longer your friend or what?
youtube.com

Answer 3

draw and fill and get this

Answer 4

Here the corner is rounded, so it's easier to draw this shape with a pen

Answer 5

Triangle ( : ?? easy...
You create a smart object.. see below, (you can create anything)
I hope everything is clear from the screenshots ...
screen = 2