The anterior triangle occupies the side of the neck in front of sternomastoid muscle. Each triangle presents boundaries in front:
Boundaries of anterior triangle are:
Anteriorly by the median plane.
Posteriorly by the sternocleidomastoid.
Superiorly by the base of the mandible and by a line joining the angle of
mandible to the mastoid process.
The apex of the triangle lies above the manubrium sterni