๐ What is a Quadrilateral?
A quadrilateral is a shape that has four sides. The prefix 'quad-' means four, like in 'quadruplets' (four babies!). These sides are straight, and the shape is closed, meaning all the lines connect. Examples include squares, rectangles, parallelograms, and trapezoids. The angles inside a quadrilateral always add up to $360$ degrees!
- ๐ Definition: A closed, two-dimensional shape with four straight sides.
- ๐ Angles: The interior angles always sum to $360^{\circ}$.
- ๐ผ๏ธ Examples: Squares, rectangles, rhombuses, parallelograms, trapezoids.
๐ What is a Polygon?
A polygon is a closed, two-dimensional shape with straight sides. The word 'polygon' comes from the Greek words 'poly' (meaning many) and 'gon' (meaning angle). Polygons can have any number of sides, as long as there are at least three. Triangles, squares, pentagons, hexagons โ they're all polygons!
- ๐ Definition: A closed, two-dimensional shape with three or more straight sides.
- โพ๏ธ Sides: Can have any number of sides (3 or more).
- โจ Examples: Triangles, quadrilaterals, pentagons, hexagons, octagons, etc.
๐ Quadrilateral vs. Polygon: The Key Differences
| Feature |
Quadrilateral |
Polygon |
| Definition |
A four-sided shape. |
A shape with three or more sides. |
| Number of Sides |
Always four. |
Three or more. |
| Examples |
Square, rectangle, rhombus, trapezoid. |
Triangle, square, pentagon, hexagon, etc. |
| Relationship |
A special type of polygon. |
A broader category that includes quadrilaterals. |
๐ก Key Takeaways
- โ
All quadrilaterals are polygons. This is because a quadrilateral is a closed shape with straight sides.
- โ Not all polygons are quadrilaterals. Polygons can have any number of sides greater than or equal to three. If a polygon has other than four sides, itโs not a quadrilateral.
- ๐ Think of it this way: Quadrilateral is a specific type of polygon, like how a square is a specific type of rectangle.
