This question already has an answer here:

I want to make a perfectly equilateral triangle but with curved corner and curved sides (not just rounded corners)

I tried to use the polygon tool with the "Smooth Corners" option and got this:

My triangle

It's close to what I want, but I want to be able to control the roundness more. I want it to be a bit more sharper

How do I do this while keeping it still perfectly equilateral?

I'm using Photoshop CC 2014, btw.

Is this even possible in Photoshop? I'm open to suggestions on using other programs if it is impossible

Any help will be appreciated!

marked as duplicate by Ryan Jul 19 '17 at 18:02


  • I usually do it on Illustrator, the vector tools in Photoshop are very limited. I don't know if someone else has any solution that does not involve manually adding the points. – Luciano Jul 19 '17 at 11:44
  • Shame, can you explain in detail how to do it in Illustrator? Because I'm extremely unfamiliar with the program compared to Photoshop – gn pan Jul 19 '17 at 11:57

While it is possible to do this in Photoshop, Illustrator CC makes the job much easier since it has a Live Corners function, where you can adjust the corners equally on all sides at the same time.

Anyhoo, you asked how to do it in Photoshop, so here's one way, although it can be a bit tricky since the corner adjustments are done manually.

  1. Draw the triangle without rounded corners.

  2. Use the Add Anchor Point tool to add anchors adjecent to the corners

  3. Use the Delete Anchor Point tool to delete the corner anchors

  4. Use the Direct Selection tool to adjust the Bezier handles to get curves.

diagram showing where to place anchors

Edit to original answer:

Further manual editing of the curves using the Direct Selection tool can be done to the triangle as necessary.

Editing Bezier Curves

  • But how do you make the sides curved too like in my screenshot? – gn pan Jul 19 '17 at 13:00
  • @gnpan You'd have to adjust the curves manually. See my edit. – Billy Kerr Jul 19 '17 at 13:28
  • Is there any way to place those additional anchor points perfectly equilaterally without eyeballing? I'm willing to do it in Illustrator if it's not possible in Photoshop – gn pan Jul 19 '17 at 14:14
  • @gnpan - I suppose you could add guides and measure the distances exactly using the Ruler tool. It's going to be difficult to get it exact. As others have said, Illustrator is better for creating vectors. – Billy Kerr Jul 19 '17 at 14:18
  • Can you show me how you would do it in Illustrator? – gn pan Jul 19 '17 at 14:34

What you want is a rounded Reuleaux triangle. It is drawn with with just a bunch of circle arcs. This is a special case (equilateral triangle) of the curve of constant width you'll find on Wikipedia. Some more explanations here.

I have a Gimp script to create them (as paths):

enter image description here

but a bit too experimental to be described here. If you are interested by the script ask here.
