Vertex Angle of Isosceles Triangle is the angle included by the legs, opposite to the base of the Isosceles Triangle. And is denoted by ∠Vertex. Vertex Angle of Isosceles Triangle is usually measured using the Degree for Angle. Note that the value of Vertex Angle of Isosceles Triangle is always positive. Typically, the value of Vertex Angle of Isosceles Triangle lies in the range from 0 to 180.