编写一个三角形类，能根据3个实数构造三角形对象，如果三个实数不满足三角形的条件，则自动构造以最小值为边的等边三角形。输入任意三个数，求构造的三角形面积。-Preparation of a triangle class, according to three real objects constructed triangle, if the triangle does not meet the three conditions of a real number, is automatically constructed to a minimum of side an equilateral triangle. Enter any three numbers, find the structure of the triangle area.