Timber conversion methods in civil engineering and carpentry Pick the correct statement(s) about sawing methods used to convert logs into boards:

Introduction / Context:
Sawing methods determine board appearance, dimensional stability, and structural behavior. Civil engineering materials and building construction syllabi commonly test recognition of tangential (plain), quarter, and radial (rift) sawing. Understanding how the cut intersects growth rings and medullary rays explains performance differences in use.

Given Data / Assumptions:

• Boards are cut from sound logs of typical softwood or hardwood species.
• Annual rings are the visible growth rings; medullary rays are radial cellular structures.
• Standard woodworking nomenclature is applied.

Concept / Approach:
Tangential (plain) sawing cuts boards roughly parallel to annual rings, maximizing yield and speed but increasing tendency to cup. Quarter sawing first quarters the log; boards are then sawn so that ring angles are typically 45° to 90°, improving dimensional stability and revealing ray fleck in some species. Radial (rift) sawing aims perpendicular to growth rings (parallel to rays), producing very stable, uniform grain, though with lower yield and higher cost.

Step-by-Step Solution:
Relate each named method to the orientation between the saw kerf and annual rings.Match definitions: tangential ≈ parallel to rings; quarter sawn ≈ 45°–90° ring angle after quartering; radial ≈ perpendicular to rings, parallel to rays.Conclude that all three statements accurately describe their respective methods.

Verification / Alternative check:
Dimensional changes occur mainly tangential to rings; the more perpendicular a board is to rings (quarter/radial), the more stable it will be—consistent with the definitions above.

Why Other Options Are Wrong:
Since each individual statement is correct, selecting only one would ignore the completeness of the methods; therefore the combined choice is best.

Common Pitfalls:
Confusing quarter sawing with pure radial sawing; quarter sawn boards span a range of ring angles, not solely 90°. Assuming tangential boards are inferior in all cases—while economical, they are appropriate when aesthetics and cost dominate.

Final Answer:
All of the above.