Architectural Working Drawings — Roof pitch 5/12 means the roof rises 5 inches for every 12 inches of horizontal run; it does not mean a rise of 2 1/2 inches per 14 inches. For a 14-inch run at 5/12, the rise would be 14 * (5/12) = 5.833 inches (approximately).

Introduction / Context:
Roof pitch expresses the amount of vertical rise for a given horizontal run. In North American notation, a pitch written as 5/12 means “5 inches of rise for every 12 inches of run.” Misreading this ratio leads to incorrect slopes, frame cuts, and flashing details. The statement provided gives a mismatched pair (2 1/2 inches per 14 inches) that does not correspond to 5/12 pitch.

Given Data / Assumptions:

• Pitch = rise/run in inches per 12 inches of run.
• Given pitch: 5/12.
• Comparison run: 14 inches.

Concept / Approach:
The relationship is linear for uniform pitch: rise = run * (rise_per_unit_run). Therefore, for any run length R, rise = R * (5/12) when the pitch is 5/12. Any other pair that does not satisfy this proportion is incorrect for that pitch and would yield the wrong rafter geometry.

Step-by-Step Solution:
1) Interpret 5/12 as rise_per_inch = 5/12 inches per inch of run.2) Compute rise for 14 inches of run: rise = 14 * (5/12).3) Perform multiplication: 14 * 5 = 70; 70 / 12 = 5.833… inches.4) Compare to 2.5 inches (2 1/2 inches): 5.833 ≠ 2.5, so the claim is false.

Verification / Alternative check:
Use proportional scaling: If 12 inches of run produce 5 inches of rise, then doubling the run to 24 inches would produce 10 inches of rise. By the same logic, 14 inches must produce more than 5 inches—again proving that 2.5 inches is too small.

Why Other Options Are Wrong:
“Correct only for flat roofs” is meaningless because flat roofs do not use 5/12; measuring along the rafter (hypotenuse) is not how pitch is defined; changing units to centimeters preserves ratios and does not make the wrong numbers right; “Correct” contradicts the calculation.

Common Pitfalls:
Confusing run measured horizontally with sloped rafter length; swapping numerator and denominator; mixing feet and inches without converting consistently.

Final Answer:
Incorrect