PROGRAM TriangleIMPLICIT NONEREAL :: a, b, c, AreaPRINT *, 'Welcome, please enter the&&lengths of the 3 sides.'READ *, a, b, cPRINT *, 'Triangle''s area: ', Area(a,b,c)END PROGRAM TriangleFUNCTION Area(x,y,z)IMPLICIT NONEREAL :: Area ! function typeREAL, INTENT( IN ) ::...