Answer:
D. 13
Explanation:
You just have to plug in numbers then solve.
(1,9) and (1,-4). Every coordinate is placed as (x,y)
(1,9) is labeled as (x1, y1)
(1,-4) is labeled as (x2,y2)
Now plug in the numbers.
d= Square root of (1-1)^2 + (-4-9)^2
d= Square root of 1^2 +-13^2
d= Square root of 1+169
d= Square root of 170
d= 13.04
Rounded to a whole number, the answer is 13