ما هي المسائل المسماة "مثلثات عثمان" و"مربعات ابن مسعود" وما حلولها؟

Ibn Mas'ud's four squares are five inheritance issues attributed to Ibn Mas'ud due to his differing opinion from the majority. They are:

1. Daughter, full or paternal sister, and grandfather: According to Ibn Mas'ud, the daughter receives one-half, and the remainder is divided equally between the grandfather and the sister (out of 4). According to the majority, the remainder is divided into thirds between the grandfather and the sister (out of 6). 2. Husband, mother, and grandfather: According to Ibn Mas'ud, the husband receives one-half, and the remainder is divided equally between the mother and the grandfather (out of 4). According to the majority, the mother receives one-third of the remainder after the husband, and the grandfather receives one-sixth (out of 6). 3. Wife, mother, grandfather, and maternal brother: According to Ibn Mas'ud, the estate is divided into quarters among them (out of 4). According to the majority, the wife receives one-quarter, the mother receives one-third, and the remainder is divided equally between the grandfather and the brother (out of 24). 4. Wife, full or paternal sister, and grandfather: According to Ibn Mas'ud, the wife receives one-quarter, the sister receives one-half, and the remainder goes to the grandfather (out of 4). According to the majority, the wife receives one-quarter, and the remainder is divided into thirds between the grandfather and the sister (out of 4). This is known as the "majority square" (Murabba'at al-Jama'ah). 5. Mother, full or paternal sister, and grandfather: According to Ibn Mas'ud, the sister receives one-half, and the remainder is divided equally between the grandfather and the mother (out of 4).

This fifth issue is called "Al-Kharqa'" due to the extensive disagreement among the Companions regarding it. It is also known as "Al-Uthmaniyyah," "Al-Muthallathah," "Al-Musabba'ah," or "Al-Musaddasah" due to the multitude of opinions concerning it. Furthermore, it is called "Al-Mukhammasah" because five Companions held differing views on it, and "Al-Sha'biyyah" and "Al-Hajjajiyyah" due to the story involving Al-Sha'bi and Al-Hajjaj.