<prompt> Codman triangle is seen inEwings sarcomaOsteosarcomaMadura footAll of the above  <response>: Codman triangle is a term used to describe the triangular area of subperiosteal bone that is created when a lesion, often a tumor, raises the periosteum away from the bone. Plain X-ray Irregular destruction in metaphysis. New bone formation. Periosteal reaction. Sunray appearance or hair on end - tumor grows into the overlying soft tissue. Codman;s triangle - area off sub periosteal new bone formation seen at the area of tumor -host coex junction. REF : MAHESWARI 9TH ED 