On the GED math test you might be given a coordinate grid with points on it and asked what the distance is between two of those points. For example, let’s say you are shown this grid:
and then asked what the distance is between points C and D. Since C and D are on the same line, all you have to do is count the spots from C to D.
The answer is 2 units.
Same thing goes if you were asked for the difference between B and D, since they are also both on the same line.
The answer is 3 units.
But what if you were asked what the distance between A and C are? Since they aren’t both on the same line, you can’t only count spaces to arrive at the answer. This is the kind of situation on the GED math test where you would refer to the formula sheet given to you. On that sheet you will find this formula:
This may look complicated but all this really is is another way to write a²+b²=c²
All you need to do is count how many spaces away C is from A up or down, and how many spaces away C is from A left or right, add those two numbers, find the square root of that, and there’s your answer.
Although the formula says (x2-x1)2 and (y2-y1)2 you don’t really need to subtract x1 from x2 or y1 from y2, just count over to find the numbers you need to square.
So you need to square 3 to find x2 and square 4 to find y2.
Since 3² = 9 and 4² = 16:
Therefore the distance between points A and C is 5 units.
The video below goes through this procss step-by-step.