Stair Terminology – Name of approximately triangular stone blocks used as steps In stone stair construction, the steps formed from blocks that are approximately triangular in plan (used to turn the stair without a landing) are called:

Introduction / Context:
When a stair turns through an angle without an intermediate landing, the treads near the turn become triangular or wedge-shaped. In traditional stone construction, these are hewn from blocks to suit the geometry and are known by a specific term.

Given Data / Assumptions:

• Steps are wedge-shaped in plan (approximately triangular).
• Material is stone, not precast concrete or timber.
• Function is to turn the flight (similar to “winders”).

Concept / Approach:
Wedge-shaped turning steps are commonly called winders. In stonework, the term “spandrel steps” is used historically for the triangular blocks that form these turning treads, set around a newel or along a curved soffit, depending on the stair type.

Step-by-Step Solution:
Identify geometry: triangular/wedge plan.Relate to usage: turning a stair without a landing.Match terminology: spandrel (winder) steps.

Verification / Alternative check:
Architectural dictionaries and conservation texts reference spandrel/winder stones in historic spiral and dog-leg staircases.

Why Other Options Are Wrong:

• Built-up steps/stone steps: generic terms, not specific to wedge-shaped turning treads.
• Newel steps: emphasize the central newel support, not the triangular geometry per se.
• “None of these”: incorrect because a standard term exists.

Common Pitfalls:
Confusing “spandrel” with the spandrel of an arch; the context here is stair steps shaped for plan rotation.

Final Answer:
Spandrel (winder) steps