Acetabular index or acetabular angle of Sharp

Stanford MSK Atlas of MSK Measurements

HIP

DEFINITION:
using the AP view of the hip, angle formed between lateral margin of acetabular roof or lateral sourcil (E) and inferior aspect of the pelvic "teardrop" (TD) and horizontal line between the inferior aspect of both pelvic "teardrops"

ABNORMAL:
if > 38 degrees then acetabular dysplasia ( RID3737 )

RADLEX:
hip ( RID2639 ), hip joint ( RID2640 ), acetabulum ( RID2564 ), pelvis ( RID2507 )

how to draw the acetabular index or acetabular angle of sharp