Final answer:
Use the Pythagorean theorem to calculate the length of the line segment as the hypotenuse of a right triangle formed by the x and y displacements between the two points in a coordinate plane.
Step-by-step explanation:
To calculate the length of a line segment using the given coordinates and the ruler postulate, you can use the Pythagorean theorem. If the line segment is represented by a straight line between two points in a coordinate plane, the length is the hypotenuse of a right triangle formed by the x-axis and y-axis displacements. By labeling one point as (x1, y1) and another as (x2, y2), the differences in x (dx) and y (dy) can be calculated as dx = x2 - x1 and dy = y2 - y1. Applying the Pythagorean theorem, you get the length of the hypotenuse (c), or the segment length, by computing the square root of the sum of squares: c = √(dx² + dy²).