By definition, Height of triangle Is a line segment. Since a triangle has three sides, it has three heights.
Set angle A, B, C of △ ABC Opposite side They are a, b, c respectively, p=(a+b+c)/2 1. Acute angle Height of triangle Are inside the triangle; The high school of an obtuse triangle has two on the outside of the triangle; right triangle There are two triangles in our high school Right angled side 。 2. The high line of a triangle Is long ： ..............._______
ta=(2/a)√p(p-a)(p-b)(p-c)；
..............._______
tb=(2/b)√p(p-a)(p-b)(p-c)；
..............._______
tc=(2/c)√p(p-a)(p-b)(p-c)。
3. The three heights of a triangle intersect at a point, which is called triangular orthocenter 。 It is often recorded as point H. 
