How do you use coordinate geometry to prove that a triangle is a right triangle

Askate shop rents roller skates as shown on the table below. which graph and function models this situation?

An unknown number x is at most 10. which graph best represents all the values of x? number line graph with closed circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the left. number line graph with closed circle on 10 and shading to the left.

If two points are given,then exactly one line can be drawn through those two points.which geometry term does the statement represent