Research the rules for finding the coordinates of a point. The rules may be slightly different if you are finding the coordinates of a point on a graph versus finding the coordinates of a point within a triangle, so it is important that you research carefully to understand the concept you are trying to explain.
Understand the information fully before you write anything. For example, if you are finding the coordinates of a point on a graph, you should understand that the x-coordinate, or the first coordinate of the point, comes from finding how many spaces away from the x-axis your point is. Likewise, for the y-coordinate you will need to determine how far away from the y-axis the point is. You can find this out by counting the spaces on the graph.
Work through a problem of finding the coordinates of a point and take detailed notes about all the steps required to find the write answer. This work can serve as an example within your rules.
List all the steps that you took to complete the task. Do not skip over any steps just because they seem easy to you; they may not be easy to someone else.