Answer:
for question 7 : I think it is no
Step-by-step explanation:
if you plot the points on a quick rough sketch you will find that none of the coordinates are on the same line (which they would have to be for a straight line). No points in those 3 coordinates are the same so the there cannot be two points on the same x or y coordiante therefore there is no right-angles triangle.
If you plot the points roughly there will not be two perpendicular lines so there is no right-angles triangle.
sorry I realise this is confusing :(
Also for Question 5:
Parallel should be anything y= for example, y=6
Perpendicular should be anything x= for example x=6 as y=7 is a horizontal line and x=6 is a vertical line. Y=6 would be parallel because y=(any number with no gradient e.g. 1,2,3,4,etc.) is horizontal.