Definition
A four-sided closed geometric shape with four right angles (90°), where opposite sides are parallel and equal in length.
Plain English
A flat, four-sided shape with square corners, where the two long sides are the same length and the two short sides are the same length.
Context Anchor
Seen in aircraft drawings, sheet metal layout, repair patterns, and measurement instructions.
Derivation
From Latin 'rectus' meaning 'right' or 'straight,' and 'angulus' meaning 'angle' — literally 'right-angled.' The name describes the defining feature: every corner is a right angle.
Why Pilots Care
In aircraft maintenance, rectangular areas are often measured, marked, cut, or inspected. If the shape is not laid out with square corners and correct side lengths, a part or repair may not fit properly.
Intuition Check
Do not treat any four-sided shape as a rectangle. For a rectangle, all four corners must be square, and each pair of opposite sides must match.
Example Sentence 1
The technician cut a rectangle of aluminum sheet to fabricate the doubler for the skin repair.
Example Sentence 2
Area calculations for the stabilizer began with measuring the rectangle formed by the spar and ribs.