Simple....
using the formula
to find slope....
1.) (9,2)(4,3)
(No)
2.) (9,2)(3,4)
(No)
3.) (2,9)(3,4)
(No)
4.) (2,9)(4,3)
(YES!)
Thus, your answer.
using the formula
1.) (9,2)(4,3)
2.) (9,2)(3,4)
3.) (2,9)(3,4)
4.) (2,9)(4,3)
Thus, your answer.