Question: who worked out a system of plane geometry
[{'answer': 'the Alexandrian Greek mathematician Euclid', 'provenance': [{'wikipedia_id': '9417', 'title': 'Euclidean geometry', 'start_paragraph_id': 1, 'start_character': 55, 'end_paragraph_id': 1, 'end_character': 96, 'bleu_score': 0.668740304976422, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '9417', 'title': 'Euclidean geometry', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 829, 'bleu_score': 0.958234925530495, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13054372089269442718}, 'section': 'Section::::Abstract.'}]}]