PROGRAM:DISTANCE
Disp "sqrt((X2-X1a)^2+(Y2-Y1)^2)"
Pause 
Disp ""
Disp "X1"
Input A 
Disp "Y2"
Input B
Disp "X2"
Input C
Disp "Y2"
Input D
Disp ""
Disp "sqrt("
Disp (C-A)^2+(D-B)^2
Pause 
Disp ""
Disp sqrt((C-A)^2+(D-B)^2)