Solution:

Qutbdin Aibek started the construction of Qutb Minar. It was completed by Iltutmish.
Its height is 73 metres. It is the world’s tallest brick minaret.
The Qutab Minar is tall with 378 steps leading to the top. The diameter of the base is 14.3 meters wide while the top floor measures 2.75 meters in diameter.
Quwwat-ul-Islam mosque is the earliest extant mosque built by the Delhi Sultans.
Qutbdin Aibek was first Muslim ruler of Delhi. He was the first ruler of Slave Dynasty.
He was succeeded by Iltutmish.
The other important rulers of Slave dynasty were Razia Begum and Balban.