trigonometric Outer center is called trigonometric outer center.

trigonometric outer circle center is trigonometric tripartite vertical bisector line intersection, trigonometric three vertices on this outer circle

trigonometric tripartite vertical bisector line intersection point, called trigonometric outer center.

The distance from the outer center to the three vertices is equal.

trigonometric vertex circle is called trigonometric outer circle, outer circle center is trigonometric outer center, this trigonometric is called this circle inner trigonometric.

(1) The outer center of the acute trigonometric is inside the trigonometric;

(2) The outer center of a right-angled trigonometric is on the hypotenuse, and the midpoint of the hypotenuse coincides;

(3) obtuse trigonometric outer center outside trigonometric

(4) equilateral trigonometric outer center and inner center are the same point.