I know that the second shape is a squircle, but what are the other shapes called? Is there an actual name for them?
The shapes do not simply have rounded corners, but the sides have a “circularity”. Here is a triangle with rounded corners next to the shape that I do not know the name of:
“Trircle”, “Triarcle”, and “Pentircle” do not seem to be used for them, at least Google’s image search does not provide any results.
“Squircle” was a random mash-up someone somewhere came up with and it became trendy. But a square with rounded corners, is still a square. And a circle with any corner is no longer a circle.
There are no specific names for the shapes merely because they have rounded corners. A triangle is still a triangle regardless of how round the corners may be. The defining factor is the number of sides, not the corners.
Now you can try and start your own trend the way “squircle” is a trend…. invent your own names…. then use them constantly, repeatedly, in every way you possibly can. Maybe they’ll catch on.