program integr
        implicit none

	real :: x, x1, x2, x3, b, b1, b2, b3, I
 
 
        !h=(b-a)/3
        
        x = 0.0
        b = (sin(x))**2.0
 
        x1 = 3.141592/6.0
        b1 = (sin(x1))**2.0
 
        x2 = 3.141592/3.0
        b2 = (sin(x2))**2.0
 
        x3 = 3.141592/2.0
        b3 = (sin(x3))**2.0
 
        I = x3*(b + 3.0*b1 + 3.0*b2 + b3)/8.0
        
        Print *,"La Integral numerica es  ", I   
        
 
        end program integr