Answer:
The answer is √74 = 8.6023
Magnitude of a line between two points can be written as
√( c - a)² + ( d - b)²
Where (a,b) and (c ,d) are two points
A(3,-1) and B(-2,6)
Magnitude of AB = √ ( -2 - 3)² + ( 6 + 1)²
= √ (-5)² + 7²
= √ 25 + 49
= √74 units = 8.6023 units
Hope this helps you.