Adjacent cells are cells that are together, and do not have other cells between each other. A cell beside another one are together called adjacent cells, as are cells that are above or below each other and touching. So A1 and A2 are adjacent cells, as are B1 and C1. A1 and C1 are not adjacent cells as B1 is between them. A1, B1 and C1 would be adjacent cells.
Non-adjacent cells are cells that do not touch each other. A1 and C3 are non-adjacent for example. For any cell, a cell immediately above, below, left or right of it is adjacent. All other cells are non-adjacent to that cell.
A range.
I'm not very interested in nonadjacent properties.
Ajt
a cornere
Sometimes they are, sometimes they are not.
congruent
diagonal
Adjacent angles share a vertex and one ray, while any two angles that don't share both those things are nonadjacent.
Vertical
diagonals
Verticle angles.
Vertical