Question 987825
First, put all equations in the "slope-intercept" form: {{{y=mx+b}}}

If two lines are perpendicular, their slopes are the negative reciprocal of each other.
If two lines are parallel, their slopes are same.
If the slope values are not the same, so the lines are not parallel. 
If the slope values are not negative reciprocals either, so the lines are not perpendicular. Then the answer is "neither".

you are given:

1. {{{y = 4/3}}}.....eq.1
2. {{{-4x = 3}}}.....eq.2
3. {{{x = 4/3}}}......eq.3

put all equations in the "slope-intercept" form


1. {{{y = 0*x+4/3}}}.....eq.1=> slope is {{{m=0}}}, y-intercept is {{{b=4/3}}}; so, this line is a horizontal line that intercept y-axis at {{{4/3}}}

2. {{{-4x = 3}}}.....eq.2 => {{{0=4x+3}}}=>{{{4x=-3}}}=>{{{x=-3/4}}}, the line is vertical and slope is {{{ undefined}}}, x-intercept is {{{x=-3/4}}}; 

3. {{{x = 4/3}}}......eq.3=>{{{x=4/3}}}, the line is vertical and slope is {{{ undefined}}}, x-intercept is {{{x=4/3}}}

so, line 1 (which is horizontal line) and 2 (which is vertical line) are {{{perpendicular}}} to each other

so, line 1 (which is horizontal line) and 3 (which is vertical line) are {{{perpendicular}}} to each other

so, line 2 (which is vertical line) and 3 (which is vertical line) are {{{parallel}}} to each other

{{{drawing( 600, 600, -10, 10, -10, 10,
line(4/3,10,4/3,-10),
line(-3/4,10,-3/4,-10),
graph( 600, 600, -10, 10, -10, 10, 4/3,4/3)) }}}