Some possible answers:

TO CROSS
REPEAT 2 [ FD 90 RT 90 FD 30 RT 90 ]
FD 30 LT 90 FD 30 RT 90 FD 30 RT 90
REPEAT 2 [ FD 90 RT 90 FD 30 RT 90 ]
END
First...
TO RECTANG
REPEAT 2 [ FD 90 RT 90 FD 30 RT 90 ]
END
Then...
TO MOVEIT
FD 30 LT 90 FD 30 RT 90 FD 30 RT 90
END
Finally...
TO CROSS
RECTANG
MOVEIT
RECTANG
END