You might want to consider using curves for this. First create shamrock shape with a 1-degree curve. Then use curve>offset to offset inward or outward. Then create surface from the two curves by lofting between them. Then extrude for thickness.

Cheers


EDIT: I am assuming you wanted a clover with an open center. The approach would differ for a solid clover. Such as using a planar to cap the sides.