1.
What is a polygon?
Correct Answer
B. A closed shape with straight lines
Explanation
A polygon is defined as a closed, two-dimensional shape composed of straight line segments connected end to end. Each segment meets only two others, one at each endpoint, and precisely at the vertices. This structure forms a clear path, with no curves involved, distinguishing polygons from shapes like circles that consist entirely of curves. Therefore, identifying a polygon involves recognizing these straight, connected segments forming a closed loop, which disqualifies any shapes with curves or open segments as true polygons.
2.
How many sides does a triangle have?
Correct Answer
A. Three
Explanation
A triangle is characterized by having exactly three straight sides and three angles. The definition of a triangle as a polygon with the fewest number of sides makes it a fundamental shape in both geometry and polygon studies. The simplicity of its structure—three edges and three vertices—forms the basis for defining and classifying more complex polygons. Each side connects directly to two others at a vertex, and this configuration ensures stability and the property of being a two-dimensional figure.
3.
What is a regular polygon?
Correct Answer
B. All sides and angles are equal.
Explanation
A regular polygon is a highly symmetrical figure, distinguished by having all sides of equal length and all interior angles of equal measure. This equality in sides and angles ensures uniformity in its appearance and properties, which simplifies calculations such as area and perimeter. Regular polygons represent the idealized form of polygons where each segment and angle is identical to the others, contributing to both aesthetic appeal and practical applications, like tiling patterns and architectural elements.
4.
What makes a polygon irregular?
Correct Answer
A. Unequal side lengths or angles
Explanation
An irregular polygon does not have all sides of equal length or all angles of equal measure, which sets it apart from regular polygons. This variability can involve any combination of different side lengths and angles, leading to a less uniform and more complex geometric figure. Irregular polygons are common in real-world applications where perfect symmetry is not required or desired, offering more flexibility in design and construction than their regular counterparts.
5.
Which polygon is also known as a quadrilateral?
Correct Answer
D. Square
Explanation
A square, as a type of quadrilateral, has four sides, making it a polygon with specific characteristics: all sides are equal in length, and all interior angles are 90 degrees. In geometry, a square is recognized for its equal sides and right angles, making it both a specific type of rectangle (all angles are right angles) and a rhombus (all sides are equal), hence its categorization as a quadrilateral, which merely requires four sides.
6.
How many sides does a dodecagon have?
Correct Answer
B. 12
Explanation
A dodecagon is defined by having twelve sides. In the realm of polygons, the number of sides directly determines the classification of the shape. The dodecagon is a more complex polygon, typical in advanced geometric studies, where its properties, such as angle sums and symmetry, provide rich mathematical exploration. Each additional side beyond the common shapes like triangles or quadrilaterals introduces new dimensions to the calculations and potential applications, especially in tessellations and decorative arts.
7.
What is the sum of the interior angles of a hexagon?
Correct Answer
B. 720 degrees
Explanation
The sum of the interior angles of a hexagon can be calculated using the formula for any polygon’s interior angles: (n−2)×180 degrees, where n is the number of sides. For a hexagon, n=6. Applying the formula, (6−2)×180=720 degrees. This calculation is fundamental in understanding how polygonal angles increase with additional sides, providing insights into both geometric properties and practical applications, such as designing objects or spaces with specific angle requirements.
8.
What distinguishes a convex polygon?
Correct Answer
A. All interior angles are less than 180 degrees.
Explanation
A convex polygon is characterized by all interior angles being less than 180 degrees. This attribute means that no part of the polygon extends inward, and a line drawn between any two points inside the polygon will not exit the boundary of the shape. Convex polygons are easier to analyze and use in many applications, including computer graphics and architectural design, because their simple, outward-extending nature avoids complexities associated with concave polygons that might have inward-extending regions.
9.
Which polygon does NOT have parallel sides?
Correct Answer
C. Triangle
Explanation
Among the given options, the triangle is unique because it does not have parallel sides, distinguishing it from parallelograms, rectangles, and rhombuses, which all have pairs of parallel sides. The lack of parallel sides in a triangle simplifies certain geometric analyses but limits the triangle's use in applications requiring parallelism, such as grid layouts or tiling that seamlessly align across multiple repetitions.
10.
What is the minimum number of sides a polygon can have?
Correct Answer
B. Three
Explanation
The minimum number of sides a polygon can have is three, as this is the smallest number of straight lines that can enclose a space and form a closed figure. With fewer than three sides, the figure cannot enclose a space, thus not meeting the fundamental definition of a polygon. This minimum count establishes the triangle as the most basic polygon, which serves as the building block for understanding all more complex polygonal shapes.