A triangle face shape is a somewhat less common shape than others, even though there are in fact two different triangle face shapes. The first is a base-up triangle, in which the forehead is wide and tapers to a narrow chin. A base-down triangle is characterized by a wide, square jawline with a much narrower forehead. Both of these can be considered a triangle face shape, and both typically have fairly pronounced cheekbones, sometimes even giving the face more of a pear shape. The best haircuts and glasses for a triangle face will vary based on the type an individual has.
A person who has a base-up triangle face shape may also be referred to as a heart face shape, if the hairline is shaped like a heart, sometimes also referred to as a widow's peak. This person will have a wide forehead that gradually tapers down to a narrow, often pointed, chin. Smaller or rimless glasses are typically recommended for this face shape to avoid making it look top-heavy. A hairstyle that falls under the chin and adds some extra weight there is generally the most flattering, to balance the wideness of the forehead and make the face look more symmetrical.
These features are different on a base-down triangle face shape, which is the reverse of the situation previously described. People with this face shape will have a wide, square jawline, but rather than a square face shape in which a broad forehead is common, these people will have a narrow forehead. In order to balance this face shape, wider glasses may be worn to help the top of the face look more broad. A hairstyle with more volume and lift on the top and sides of the head can also help to balance this relatively uncommon face shape.
Generally, other facial features are pretty similar with either face shape. Cheekbones are often very pronounced in these face shapes, which can sometimes even make the face look pear-shaped. Again, different haircuts, glasses, or even makeup changes can really help to highlight or minimize certain facial features. There are a number of different websites that allow individuals to upload a photo of themselves, and then "try on" different looks without actually having to attempt different hairstyles or glasses, which can be very helpful to get an idea of what looks good with these facial features.