I am sorry, that is not enough information. You have to show us the graph.
Answer:
52 cm
Step-by-step explanation:
Use the pythagorean theorem to solve for missing sides in a right triangle.
20²+48²= missing side
20²+48²=2704
Take the square root of 2704 to get the missing side.
A points location will change after you add a negative value to the y coordinate even if you leave the x coordinate the name because you are changing the value of the y coordinate. For example, if you have (4,6) as a coordinate and then change it to (4,-6), the coordinate will now just be on the other side of the x axis