A line that is perpendicular to a line with slope m has slope -1/m which is the opposite reciprocal of the original slope.
In this case the original line in standard form is
2x-4y=-8
transform this into slop intercept form
-4y=-2x-8
4y=2x+8
y=(1/2)x+2
The slope of this original line is 1/2 therefore the perpendicular line will have slope -2
y'=2x'+b
then substitute in the order pair (x',y')
1=2(-2)+b
b=5
Therefore equation of line is
y=2x+5
The graph is just following this equation!
If you have any questions about my explanation please ask I will answer them to the best of my ability.