Answer:
In an ideal intercuspal position, the mesiofacial groove of a mandibular first molar opposes "A triangular ridge of the mesiofacial cusp" of the maxillary first molar
Explanation:
Triangular ridges are those which arises from the cusp guidelines of premolar and molars near the central groove. Transverse ridges are designed by the grouping of two triangular ridges on the posterior teeth. The connection of the buccal and lingual triangular ridges is frequently termed as an example. Being a non-functional cusp it is a mandibular tooth. The crown touches into lingually. The cusp has four cusp edges they are mesiobuccal, distobuccal, mesiolingual and distolingual. The buccal and lingual triangular edges will lead to the establishment of the transverse edge in the central groove part.