Area of a Special Spherical Triangle.

Calculate the area of a special spherical triangle, which is formed by intersecting of a sphere and three mutually perpendicular planes. The intersection point of the three planes lies inside of the sphere. The result of the calculation is not an approximate solution but an analytic one. The analytical expression shows that the area of spherical triangle, under the radius of a sphere being known, is only determined by the contact angles. The conclusion can be used in the research of nucleation theory of crystallography. [ABSTRACT FROM AUTHOR]