<prompt> Postero lateral anconeus triangle is formed byHead of radius, lateral epicondyle, medial epicondyleHead of radius, lateral epicondyle, olecranonOlecranon, medial epicondyle, neck of radiusNeck of radius, head of radius, lateral epicondyle  <response>: B i.e. Head of radius, lateral epicondyle, olecranon Radial head, lateral epicondyle and tip of olecranonQ form a triangle over the posterolateral aspect of elbow joint. This space is occupied by anconeus inuscle2 and so known as anconeus triangle. 