Designs By Mark - Photoshop Tips - Making a Triangle
How to make a triangle Ok first follow these 4 steps below.
Ok now go back to your work area and hold down the Shift key and drag out a Arrowhead, but don't draw the tail of it, just the triangle part. If you want a bigger Triangle, then change the "Weight" of your shape in the line options like shown above. You can make it as big as the screen if you want to.