Question

Why Shahjahan built Shahjanabad?

Answer 1

ans1))Shahjahanabad is the city built by the shah jahan , a Mughal Emperor This city is also today known Old Delhi the construction of which completed in the year 1648.

This city have the shape like quarter circle in which a Red fort built in the center. This was having the approximate 14 gates
This city was remained the capital of the emperor after it is completed built  
This city main street also have  a canal but the main street name changed to "Chandni chowk" which start from red fort.

ans2))Shahjahanabad was set up in 1638 by the Mughal Emperor Shahjahan on the western bank of the river Yamuna. The city is popularly known as Old Delhi and is a walled city. It took a decade to complete building this city.
Shahjahanabad served as the capital of the Mughal Empire until its end in 1857. The city was home to a large number of mansions, mosques, and gardens.
Shaped like a circle, the Red Fort was the point of focus of Shahjahanabad. The whole city was bordered by a wall and had 14 gates