The screen in a theatre is 22 ft high and is positioned 10 ft above the floor, which is flat. The first row of seats is 7 ft fro
m the screen and the row are 3 ft apart. You decide to sit in the row where you get the maximum view, that is, where the angle thetha subtented by the screen at your eyes is a maximum. Suppose your eyes are 4 ft above the floor, as in the figure, and you sit at a distance x from the screen.
650 kgs is equal to 1,433 lbs. I believe the mistake would be that they forgot to add a period in between 65 and the 0, because 65.0 kgs is equal to 143.3 lbs.