this is what i need help with, the questions at the bottom i do not understand

Adventures of Sir Cumference The Mathematical Knight There is a fortress with three guard towers connected by a fortress wall. A castle tower is in the center of the fortress walls. Princess Vertexia is held hostage in the castle tower. A brave Knight, Sir Cumference, wishes to free her. For the fastest get-away, his plan is to go over the fortress wall at a point on the wall which is the shortest distance from the wall to the castle tower. He will use this precise location to enter and exit the fortress. He has mapped out the location of the guard towers and the castle tower from his hideout. He finds the original blueprints of the castle in the archives. It appears that Sir Euclid was the original designer and built the fortress on flat ground and placed the castle tower in a unique location which he called the Concurrentia of Angulus Bisectus. Respectively in terms of leagues from the hideout the guard towers are located at 3 east 5 north, 7 east 7 north, 11 east 3 north. Euclid named the castle tower In Centrum Turrim of Collocatione. The legend defines a league as 0.25 miles "Enter Sir Laughsalot" Sir Cumference converses with one of his Knights; Sir Laughsalot. Sir Laughsalot thinks he sees a problem with the plan. They need to scale the 20 ft outer wall of the fortress, rescue the princess from the 25 ft tall tower, zip-line from the top of the tower on a 180 ft rope to the ground, and scale the wall at the best exil point to get back to the hideout in the shortest distance possible from the castle, In reviewing the plan Sir Laughsalot believes there is a better exit point than any of the entry points and would result in a shorter distance back to their hideout. Sir Cumference takes a closer look but doesn't agree. Since the entry points are the shortest distances to the tower from the wall they must also be the shortest distance back to the hideout from the castle. He tries to discuss his reasoning with the Knight but he just Laughs-a-lot. 1.) Entry: Which entry location(s) provide for the shortest distance to the castle tower? 2.) Exit: Which exit point offers the most efficient route for the shortest distance back to the hideout from the castle tower? A 3.) Zipline distance: At what distance from the castle's foundation must the taut zipline be securely anchored to the ground, given that its opposite end is affixed to the top? 4.) Zipline location: To align the zipline with the optimal exit route, where should the zipline be secured to the ground? 5. ) Lookout: Is it possible that among the majestic trees surrounding the fortress, they aim to install a strategically positioned lookout, serving as a vantage point equidistant from the guard towers? Support your answer mathematically