Possible Clues:

• Parallelogram with four equal sides
• Greek character, a doctor, produces the shape
• An equilateral parallelogram
• A parallelogram (var.)
• Figure Spanish chap cut by a third after ending in gutter
• Figure on plane, extremely rich old medic
• Parallelogram type
• Oblique-angled, four-sided figure
• Diamond heads for royal head of monarch — belatedly
• Greek character, doctor, in shape