The common tie knot that produces a solid, large triangular shape is the Windsor knot.
Also called the Full Windsor, it is a broad, symmetrical knot made with several crossings of the tie’s wide end. Its substantial triangular profile pairs best with spread or cutaway collars, where a smaller knot might leave too much empty space. The knot also shortens the tie more than simpler styles, so it is often useful with longer neckties.
Despite its name, the Windsor knot was not invented by Edward VIII, the Duke of Windsor. His famously wide tie knots were reportedly helped by specially made, thicker ties; the knot later became associated with his style and was named in his honor. The name became especially established in the United States during the 1930s.
A common mix-up is the Half-Windsor, sometimes called the Single Windsor. It also creates a triangular shape, but it is smaller and less bulky. The Four-in-Hand knot is narrower and more asymmetrical, while the Full Windsor is the canonical choice when the clue emphasizes a large, solid triangle.