Question 2730: Area of a Half-Open Rectangle with Nonnegative Dimensions

Original question and givens

Use one equal-unit orthonormal Euclidean Cartesian frame. The half-open rectangle [0,4)×[0,5) has width 4 and height 5, both nonnegative. Find its area in squared length units.

• G001 — Use one equal-unit orthonormal Euclidean Cartesian frame. The half-open rectangle [0,4)×[0,5) has width 4 and height 5, both nonnegative. Find its area in squared length units.

Definition and scope

Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.

• mko-area

Step-by-step derivation

orthonormal equal-length coordinate units;half-open regions

area in squared length units

rectangle area := mul(4, 5)

rectangle area = 20

w=4; h=5

area=20; empty=No

Reverse checks

• S003 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
• S002 · premise_and_result_audit — Recompute rectangle area with exact rational arithmetic, not rounded decimals.
• S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.

Result

20

The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.

This question review and source binding

Review date: 2026-10-26

Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.