“I just bought a house and this weird triangle holder thing is by my kitchen sink. What is it?”
A: "It’s a dishtowel holder. Take the corner of your dishtowel and put it to the back of the triangle, then pull down on the towel and it’s held in place."
Thanks Internet.
"... and the liquid will drop through the slit in the middle."
Let's keep it clean; this is not an AO site.