He designed the Sears tower and the John Hancock center. He was born to a high school mathematics teacher in a small rural town in Bangladesh. He became a Fulbright Scholar as recognition of his academic excellence, and used the funding from the scholarship to travel to the US in 1952 and work in architecture. Khan challenged the current concept of how skyscrapers are structured, and developed the tube concept, which allowed for towers to possess a greater capacity to withstand high winds and vibrations from earthquakes. He is most known for his design of the Sears Tower and John Hancock Center.