Question

The endpoints of a segments are (10, 0) and (20, 0). How do you know it is a horizontal segment?

Answer 1

If its two endpoints have the same y-coordinate

Explanation:

Answer 2

if it is horitzontal, the slope will be 0

slope between (x1,y1) and (x2,y2) is (y2-y1)/(x2-x1)

(10,0) and (20,0)
slope=(0-0)/(20-10)=0/10=0
slope is 0
it is horzontal

or we could just recognize that the equation is y=0