How do you find the distance between two points on a coordinate plane with the same x-coordinate?

How do you find the distance between two points on a coordinate plane with the same x-coordinate?

• A. By doubling the y-coordinates.
• B. By finding the absolute difference between their y-coordinates.
• C. By adding y-coordinates.
• D. By dividing coordinates.

Answer: (B)

When two points share the same x-coordinate, they sit on a vertical line, so the distance between them is how far apart they are up and down. That distance is the absolute difference of their y-values: distance = |y2 − y1|. The absolute value makes sure the distance is a nonnegative number. For example, (3, 5) and (3, −2) are 7 units apart since |5 − (−2)| = 7. Doubling, adding, or dividing the y-coordinates wouldn’t measure the vertical separation between the points.

When two points share the same x-coordinate, they sit on a vertical line, so the distance between them is how far apart they are up and down. That distance is the absolute difference of their y-values: distance = |y2 − y1|. The absolute value makes sure the distance is a nonnegative number. For example, (3, 5) and (3, −2) are 7 units apart since |5 − (−2)| = 7. Doubling, adding, or dividing the y-coordinates wouldn’t measure the vertical separation between the points.