Plotting letters

This task is about giving the co-ordinates of points on a graph.
 
a)
The graph above shows a line and two points marked with an X. 
The co-ordinates of one of the points is (3,1). 
 
Write down the co-ordinates of the other point. (     ,     )
 
b)
What one other point would you need to mark to form the letter L?

Draw it on the graph, then write down the co-ordinates. (     ,     )
 
c)
What two other points would you need to mark to form the letter T?

Draw them on the graph, then write down the co-ordinates. (     ,     ); (     ,     )
 
d)
What three other points would you need to mark to form the letter K?

Draw them on the graph, then write down the co-ordinates. (     ,     ); (     ,     ); (     ,     )