In building construction terminology, the exterior angle formed between the outer faces of two meeting walls is called what?

Introduction / Context:
The geometry of wall intersections is fundamental vocabulary in brickwork and stone masonry. Accurately naming the outer corner where two wall faces meet helps in detailing, measurement, estimating, and specification for corner treatments, protections, and aesthetics.

Given Data / Assumptions:

• Two masonry wall faces meet externally forming an outer corner.
• We are asked for the specific term used in civil/architectural practice.
• Standard masonry terminology applies.

Concept / Approach:
The exterior angle between the outer faces of a wall is termed the quoin. In practice, quoins may be emphasized using special stones or bricks (quoin stones/quoins) for strength and visual accent. The word “junction” is a general meeting of parts and “turn” is not a standard technical name here. “Arris” refers to the sharp edge formed by two surfaces meeting, not the corner assembly itself.

Step-by-Step Solution:
Identify the feature: an external corner of masonry.Match to terminology: external corner → quoin.Exclude generic terms (junction/turn) and misapplied terms (arris).Therefore, the correct term is quoin.

Verification / Alternative check:
Standard building construction texts classify corners as quoins (external) and re-entrant angles (internal). Quoin stones are commonly detailed in ashlar or dressed masonry.

Why Other Options Are Wrong:

• Junction: too general; does not specify an external masonry corner.
• Turn: not a standard term for this feature.
• All of the above: incorrect since only one precise term fits.
• Arris: the sharp edge line, not the corner assembly.

Common Pitfalls:
Confusing “arris” (edge) with “quoin” (corner). Assuming any meeting is a “junction” without recognizing specific masonry terminology.

Final Answer:
Quoin (exterior corner)