Let ABC be a scalene triangle with I be its incenter. The incircle touches BC, CA, AB at D, E, F, respectively. Y, Z are the midpoints of DF, DE respectively, and S, V are the intersections of lines YZ and BC, AD, respectively. T is the second intersection of ā(ABC) and AS. K is the foot from I to AT. Prove that KV is parallel to DT. Proposed by ltf0501
geometryincenterTaiwanIranparallelincircle