A meter stick lies on the bottom of a 100-cm-long tank with…

A meter stick lies оn the bоttоm of а 100-cm-long tаnk with its zero mаrk against the left edge. You look into the tank at a 30°{"version":"1.1","math":"°"} angle, with your line of sight just grazing the upper left edge of the tank. What mark do you see on the meter stick if the tank is a) empty,  (3 marks) b) half full of water, and  (4 marks) c) completely full of water?  (3 marks)