Difficulty: Easy
Correct Answer: Incorrect
Explanation:
Introduction / Context:
This question tests your understanding of basic geometric terms. It asks whether a cube, which is a familiar three dimensional solid, can be classified as a polygon. You must recall the precise definitions of polygon and cube and decide whether the classification in the question is correct or not.
Given Data / Assumptions:
- A polygon is a flat, two dimensional figure.
- Polygons are made up of straight line segments joined end to end in a closed chain.
- A cube is a solid, three dimensional shape with six square faces, twelve edges and eight vertices.
- The statement under test says that a cube is a polygon.
Concept / Approach:
Because polygons are two dimensional and a cube is three dimensional, they belong to different categories in geometry. A cube is a polyhedron, not a polygon. While each face of a cube is a square, and a square is a polygon, the cube itself is not. To answer correctly, you must distinguish between the faces of the cube and the cube as a whole solid figure.
Step-by-Step Solution:
Step 1: Recall the definition of a polygon: it is a plane figure with three or more straight sides. Examples include triangles, rectangles, pentagons and so on.
Step 2: Note that plane figure means the shape lies entirely in a single flat plane and has only two dimensions, length and breadth, with negligible thickness.
Step 3: Consider what a cube is. A cube has length, breadth and height and occupies space in three dimensions. It is a solid object, not a flat figure.
Step 4: In geometry, such three dimensional figures with flat faces are called polyhedra, not polygons.
Step 5: Each of the six faces of a cube is a square, and a square is indeed a polygon, specifically a quadrilateral with equal sides and right angles.
Step 6: However, the fact that the faces of a cube are polygons does not mean that the cube itself is a polygon. It is a solid built from polygons.
Step 7: Therefore, classifying a cube as a polygon mixes up the categories of two dimensional shapes and three dimensional solids and is incorrect.
Verification / Alternative check:
Think of other geometric classifications. A sphere is not a circle, even though any cross section of a sphere can look like a circle. Similarly, a cylinder is not a rectangle, though unfolding its surface forms a rectangle. In each case, the solid object and the flat shape are related but belong to different geometric families. The relationship between cube and square is of the same kind: a cube is built from square faces, but it is not itself a square or any polygon.
Why Other Options Are Wrong:
Correct: This would only be acceptable if cubes were defined as polygons, which contradicts standard definitions.
Information insufficient: Geometry gives precise definitions of polygons and cubes, so there is no missing information.
Not applicable: The question is directly about classification in basic geometry, so it is fully applicable.
Common Pitfalls:
A frequent misunderstanding is to think that if a solid has polygonal faces, then the solid itself might also be called a polygon. This confusion arises from not keeping the distinction between dimensions clear. In exams, such questions are designed to check whether you know that polygons are strictly two dimensional while solids like cubes, cuboids and prisms are three dimensional polyhedra. Always ask yourself how many dimensions a shape has before assigning it to a category.
Final Answer:
The statement that a cube is a polygon is incorrect; a cube is a three dimensional polyhedron, not a two dimensional polygon.
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