7: Regular Polygons and Circles
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A polygon is traditionally a plane figure that is bounded by a finite chain of straight line segments closing in a loop to form a closed chain. These segments are called its edges or sides, and the points where two edges meet are the polygon's vertices or corners.
- 7.1: Regular Polygons
- A regular polygon is a polygon in which all sides are equal and all angles are equal, Examples of a regular polygon are the equilateral triangle (3 sides), the square (4 sides), the regular pentagon (5 sides), and the regular hexagon (6 sides).
- 7.2: Circles
- The circle is one of the most frequently encountered geometric figures. Wheels, rings, phonograph records, clocks, coins are just a few examples of common objects with circular shape. The circle has many applications in the construction of machinery and in architectural and ornamental design.
- 7.3: Tangents to the Circle
- A tangent to a circle is a line which intersects the circle in exactly one point.
- 7.4: Degrees in an Arc
- The number of degrees in an arc is defined to be the number of degrees in the central angle that intercepts the arc.
- 7.5: Circumference of a Circle
- The circumference of a circle is the perimeter of the circle, the length of the line obtained by cutting the circle and "straightening out the curves".
Thumbnail: Regular hexagon with annotation. (CC0; László Németh via Wikipedia)