Syllogism — Propagate class inclusions for geometric terms Statements: I) All squares are rectangles. II) All rectangles are polygons. Decide the best conclusion about a square based on these statements.
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ASquare is not a polygon.
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BSquare is a polygon only.
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CSquare is a rectangle and a polygon.
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DSquare is not a rectangle.
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ENone of these
Answer
Correct Answer: Square is a rectangle and a polygon.
Explanation
Introduction / Context:The prompt gives two universal inclusions about familiar geometric classes and asks you to pick the most accurate single conclusion about a square. This is a classic test of chaining inclusions without inventing extra claims or reversing directions.
Given Data / Assumptions:
- I: Squares ⊆ Rectangles.
- II: Rectangles ⊆ Polygons.
- Usual geometric meanings of 'square', 'rectangle', and 'polygon'; no other facts are assumed.
Concept / Approach:Subset chains are transitive. If Squares ⊆ Rectangles and Rectangles ⊆ Polygons, then Squares ⊆ Polygons. Importantly, this does not erase the intermediate inclusion; it preserves both relationships simultaneously: every square is (i) a rectangle and (ii) a polygon.
Step-by-Step Solution:
Step 1: Apply transitivity: Squares ⊆ Rectangles and Rectangles ⊆ Polygons ⇒ Squares ⊆ Polygons.Step 2: Keep the intermediate fact: 'All squares are rectangles' remains true while we conclude squares are also polygons.Step 3: Select the option that states both facts without adding anything extra or wrong.Verification / Alternative check:With a Venn diagram, place Squares inside Rectangles and Rectangles inside Polygons; Squares is thus inside Polygons as well. No contradiction arises, and both inclusions hold together.
Why Other Options Are Wrong:
- Square is not a polygon. Contradicts the derived inclusion Squares ⊆ Polygons.
- Square is a polygon only. Misleading/incomplete; it omits the guaranteed fact that every square is also a rectangle.
- Square is not a rectangle. Directly contradicts Statement I.
Common Pitfalls:Picking a true-but-incomplete statement when a strictly stronger, fully accurate statement is available; forgetting that subset chains preserve all links.
Final Answer:Square is a rectangle and a polygon.