Do you have a graph or a picture? It would be easier to explain
Lagrange multipliers:







(if

)

(if

)

(if

)
In the first octant, we assume

, so we can ignore the caveats above. Now,

so that the only critical point in the region of interest is (1, 2, 2), for which we get a maximum value of

.
We also need to check the boundary of the region, i.e. the intersection of

with the three coordinate axes. But in each case, we would end up setting at least one of the variables to 0, which would force

, so the point we found is the only extremum.
Answer:
1)An angle bisector is basically the division of an angle into two equal parts, so you should just draw a line in the middle after you found the angles using the compass
2) parallel lines is a pair of lines that never intersect, and are always the same distance apart. you should use the compass to draw a 90-degree angle at the end of the line XY, and use the straightedge to draw a line that is parallel to the line XY.