Main motif of this puzzle: Triangle mate
In triangle mate, a queen checkmates the king. The queen is next to the king, and protected by a rook, which is two squares away, and also next to the king. The queen, rook, and king form a triangle.
Learn more in this guide.
The hint button is in beta test. We recommend to use the button only after you've thought about the puzzle for some time without finding any idea.
Read more about the hint button in this blog post.