Which term describes areas that share a common border?

Which term describes areas that share a common border?

• A. Contiguous
• B. Noncontiguous
• C. Adjacent
• D. Disjoint

Answer: (A)

Sharing a common border is about touching along a boundary with no gaps. That idea is captured by the term contiguity. When two areas are contiguous, they meet along a border, so you can move from one region to the other through that shared edge. For example, the states in the contiguous United States all lie along land borders with their neighbors, forming a connected patch, unlike Alaska or Hawaii, which are not contiguous with the mainland.

Noncontiguous means they do not touch at all, or there’s a gap between them. Disjoint describes completely separate pieces that do not share any points. Adjacent means next to or neighboring, but in strict terms it doesn’t always demand a shared border in every context; the specific phrasing “share a common border” aligns best with contiguity.