Are congruent triangles the only triangles that can be used to show why the slope is the same between any two points on a non-vertical line? True or False??

Guys, i have a life question. so my bff that i met in school (i had to switch schools) decided she was gonna quit a game that was our only communication. she said she is never gonna be on againand i'm sad because she never responds to my texts.which means probably no more sleepovers, no more going to each others house, and no more camping together : ( all of those activities happen because i texted her on that game. what do i do?