This question is essentially asking to find the distance between these two points:
The formula for distance between two points is:
In this case:
^^^Plug these numbers into the formula for distance like so...

To solve this you must use the rules of PEMDAS (Parentheses, Exponent, Multiplication, Division, Addition, Subtraction)
First we have parentheses. Remember that when solving you must go from left to right

-4 - 1 = -5
-10 - 2 = -12

Next solve the exponent. Again, you must do this from left to right
(-5)² = 25

(-12)² = 144

Now for the addition
25 + 144 = 169
Now take the square root
= 13
This segment is 13 units long
Hope this helped!
~Just a girl in love with Shawn Mendes