How is the template of رَحْمَةٌ identified?

Noun Patterns: Jāmid, Maṣdar, Mushtaq and 50 Basic-Triliteral Maṣdar Entries

• فُعُولٌ with medial wāw
• فَعَالٌ with medial alif
• مَفْعُولٌ with initial mīm
• فَعْلَةٌ with final tāʾ marbūṭa