You have chosen the correct placement of the lines on the number line. The "or equal to" symbol (≥ or ≤) means the dots at -3 and +1 are filled in, indicating those numbers are part of the solution.
If the ">" or "<" symbol is used in the inequality, the dot is left open, as in the answer you selected. The open dot indicates that value is not part of the solution set.
2.857 m away from the wall. because if it is 1.3 m off the ground when fired then you just subtract that from 2.9 to get 1.6 then divide that by sin (38.2) to get 2.857 m from the wall.