If there is something wrong with the conditions of the triangle, it should be changed to if ((a+b >; C) and amp&(a+c >; B) and&(b+c > a))；

At the same time, we should put

area=pow((s*(s-a)*(s-b)*(s-c))，( 1/2)；

Area = pow ((s * (s-a) * (s-b) * (s-c))，( 1.0/2)； Because 1 and 2 are plastic data, the result is still plastic, that is, 1 divided by 2 equals 0, which is why you can't find your area.