The document discusses several useful radiographic lines and angles for evaluating the elbow in children. The anterior humeral line on a lateral view should intersect the middle third of the capitellum and is useful for detecting supracondylar fractures. The angle between the distal humeral shaft and metaphysis should be 30-40 degrees. The radiocapitellar line on a lateral view should pass through the center of the capitellum. Bauman's angle on an AP view measures the reduction of supracondylar fractures.