Final answer:
To find the length of line segment XY, we use the distance formula with the given points X=(1,8) and Y=(4,12), resulting in a calculated length of 5 units.
Step-by-step explanation:
The length of line segment XY can be found by using the distance formula, which is derived from the Pythagorean theorem. For two points X=(x1, y1) and Y=(x2, y2), the distance d between these points is given by:
d = √((x2-x1)² + (y2-y1)²)
Substitute the given points X=(1,8) and Y=(4,12) into the formula:
d = √((4-1)² + (12-8)²)
d = √(3² + 4²)
d = √(9 + 16)
d = √25
d = 5
Therefore, the length of line segment XY is 5 units.