Step 15: Switch To "Full Screen Mode With Menu Bar"

In a moment, we're going to be stretching the triangle upward beyond the boundaries of our canvas, which means we're going to need a bit more room to work if we want to be able to see what we're doing. If you're working with your document inside a document window, which is the default way to work in Photoshop, press the letter F on your keyboard to switch your view mode to Full Screen Mode with Menu Bar. As the name implies, this switches you to a full screen mode in Photoshop while leaving the Menu Bar in place at the top of the screen. Then, to give yourself even more room to work, press Ctrl+- (Win) / Command+- (Mac) a couple of times to zoom out. You should now have quite a bit of empty gray space around your document:

Step 16: Clear The Guides

Since we've already positioned our triangle where we want it in the exact center of the document, our guides have served their purpose and we can safely remove them. Go up to the View menu at the top of the screen and choose Clear Guides. This will clear the guides from the document:

Step 17: Stretch The Triangle Up Beyond The Top Of The Canvas With Free Transform

Press Ctrl+T (Win) / Command+T (Mac) on your keyboard to bring up Photoshop's Free Transform box and handles around the triangle. Click on the handle (the little square) in the top center of the Free Transform box and drag upward to stretch the triangle, making it longer and more narrow. Continue dragging until the triangle goes well beyond the top of the canvas, like so:

The reason why we're stretching the triangle beyond the top of the canvas will become clear in a moment. Press Enter (Win) / Return (Mac) when you're done to accept the transformation and exit out of the Free Transform command. You'll notice that even though we've stretched the triangle beyond the top of the canvas, only the part that falls within the boundaries of the canvas area remains visible in the document. The rest of the triangle above the canvas is currently visible only as an outline.

Step 18: Bring Up The Free Transform Box Around The Triangle Once Again

Press Ctrl+T (Win) / Command+T (Mac) to once again bring up the Free Transform box and handles around the triangle. I know, we just had Free Transform open a moment ago and I told you to close it, and now I'm telling you to open it again. What gives? Well, the reason is because this time, we're going to use Free Transform to rotate the triangle, and when we're done, we're going to use a little known command called Transform Again to have Photoshop repeat the rotation over and over again all around the document for us, which will create our starburst effect!

Step 19: Drag The Center Point Of The Free Transform Box Down To The Bottom Center Handle

If you look closely in the center of the Free Transform box, you'll see a small icon that looks like a little target symbol. This icon represents the rotation center point for the Free Transform command. Everything rotates around this icon, wherever the icon happens to be positioned. If we were to rotate the triangle with this icon in the center of the Free Transform box, the triangle would rotate around its center. That's usually what we want, but it's not what we want here. We want our triangle to rotate around the center of the document, which means we need to move the target icon into the center of the document.

To do that, click on the target icon, then drag it down on to the handle (the little square) in the bottom center of the Free Transform box, which will place it in the exact center of the document directly above the bottom point of the triangle. As soon as you get close enough to the handle, the icon will snap into place:

Step 20: Rotate The Triangle

With the target icon now positioned in the center of the document, we're ready to rotate the triangle. Move your mouse outside the top right corner of the Free Transform box. You'll see your mouse cursor change into a little rotation icon (a curved line with an arrow on both ends). Hold down your Shift key, which will force the triangle to rotate in increments of 15 degrees, making things much easier for us. Then, with your Shift key held down, click and drag your mouse down and to the right to rotate the triangle in a clockwise direction. You'll notice two things as you drag. One, the triangle is rotating around the center of the image, and two, it's snapping into 15 degree increments rather than rotating smoothly.

Rotate your triangle a total of 45 degrees clockwise (three increments of 15 degrees), at which point it will be extending out beyond the top right corner of the canvas:

The reason why we stretched the triangle so far beyond the top of the canvas back in Step 17 was so that it would be large enough to still extend out beyond the boundaries of the canvas even in these corner sections. Press Enter (Win) / Return (Mac) when you have your triangle rotated to accept the transformation and exit out of the Free Transform command.

Now that we've used Free Transform to rotate the triangle once, we're going to let Photoshop do the rest of the work for us, repeating the rotation all around the document to create the starburst effect!