A \(50 \ ft\) long ladder leans against a vertical wall, with its top touching the wall at a height of \(48 \ ft\). The base of the ladder is pulled \(16 \ ft\) further away from the wall. Based on this situation, answer the following questions.
1. Which geometric figure is formed here?
2. Calculate the initial distance of the base of the ladder from the wall.
3. Find the height at which the top of the ladder touches the wall after the base is moved \(16 \ ft\) away.
4. By how much does the top end of the ladder slide down the wall?