<prompt> Suprameatal triangle externally represents:Transverse sinusPromontory of middle carInternal acoustic meatusMastoid antrum  <response>: Suprameatal triangle, also known as MacEwens triangle, is seen in temporal bone of skull, in norma lateralis view.It is a small areadepression present posterior and superior to external acoustic meatus.It forms the lateral wall of mastoid antrum.It is of importance to surgeons performing cortical mastoidectomy.Boundaries of Suprameatal triangle:Superiorly: By supramastoid crest.Anteriorly: By posterosuperior margin of EAM external acoustic meatus.Posteriorly: Vertical tangent to posterior margin of EAM external acoustic meatus. Anteroinferiorly: By presence of suprameatal spine.Key Concept: Suprameatal triangle, also known as MacEwens triangle, is seen in temporal bone of skull, in norma lateralis view. It represents mastoid antrum. 