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By drawing a transverse line between the two ischial tuberosities, the diamond-shaped perineum can be subdivided into two triangles. The urogenital triangle is anterior to the line. Posterior to the line is the anal triangle (Figure 41.1).

Links and References:
Grant's: 3.59
Netter (1ed.): 354 (2ed.): 350
Rohen/Yokochi: 340