Question 1056091
{{{graph(300,300,-10,10,-10,10,-x,x,-x+4)}}}
Notice that the distance is a perpendicular line to y=-x+4 from the origin.
The line is the base of a triangle
Each leg is 4 units long.
The perpendicular is y=x
The distance is from (0,0) to (2,2). That is sqrt (4+4)=2 sqrt (2) or about 2.828 units.