geometry.pptx
- 1. EVERYDAY
- 2. A polygon is a closed figure made by joining line segments, where each line segment intersects exactly two others. Polygon
- 3. Q: Is this a polygon? Why or why not? A: No… Polygons are closed figures.
- 4. Q: Is this a polygon? Why or why not? A: No… It is not made of line segments.
- 5. Q: Is this a polygon? Why or why not? A: No… Its sides do not intersect in exactly two places each.
- 6. Regular Polygons A regular polygon is a polygon whose sides are all the same length, and whose angles are all the same. The sum of the angles of a polygon with n sides, where n is 3 or more, is 180° × (n - 2) degrees.
- 7. Are these regular polygons? Why or why not? A: No… These sides are all the different lengths, and the angles are all different.
- 8. Vertex • The vertex of an angle is the point where the two rays that form the angle intersect.
- 9. Vertex of a Polygon • The vertices of a polygon are the points where its sides intersect.
- 10. Triangle A three-sided polygon. The sum of the angles of a triangle is 180 degrees.
- 11. Equilateral Triangle A triangle having all three sides of equal length. The angles of an equilateral triangle all measure 60 degrees.
- 12. Isosceles Triangle A triangle having two sides of equal length.
- 13. Scalene Triangle A triangle having three sides of different lengths.
- 14. Acute Triangle A triangle having three acute angles.
- 15. Obtuse Triangle A triangle having an obtuse angle. One of the angles of the triangle measures more than 90 degrees.
- 16. Right Triangle A triangle having a right angle. One of the angles of the triangle measures 90 degrees.
- 17. Quadrilateral A four-sided polygon. The sum of the angles of a quadrilateral is 360 degrees.
- 18. Rectangle A four-sided polygon having all right angles. The sum of the angles of a rectangle is 360 degrees.
- 19. Square A four-sided polygon having equal-length sides meeting at right angles. The sum of the angles of a square is 360 degrees.
- 20. Parallelogram A four-sided polygon with two pairs of parallel sides. The sum of the angles of a parallelogram is 360 degrees.
- 21. Rhombus A four-sided polygon having all four sides of equal length. The sum of the angles of a rhombus is 360 degrees.
- 22. Trapezoid A four-sided polygon having exactly one pair of parallel sides. The two sides that are parallel are called the bases of the trapezoid. The sum of the angles of a trapezoid is 360 degrees.
- 23. Pentagon A five-sided polygon. The sum of the angles of a pentagon is 540 degrees. A regular pentagon: An irregular pentagon:
- 24. Hexagon A six-sided polygon. The sum of the angles of a hexagon is 720 degrees. A regular hexagon: An irregular hexagon:
- 25. Heptagon A seven-sided polygon. The sum of the angles of a heptagon is 900 degrees. A regular heptagon: An irregular heptagon:
- 26. Octagon An eight-sided polygon. The sum of the angles of an octagon is 1080 degrees. A regular octagon: An irregular octagon:
- 27. Nonagon A nine-sided polygon. The sum of the angles of a nonagon is 1260 degrees. A regular nonagon: An irregular nonagon:
- 28. Decagon A ten-sided polygon. The sum of the angles of a decagon is 1440 degrees. A regular decagon: An irregular decagon:
- 29. Circle A circle is the collection of points in a plane that are all the same distance from a fixed point. The fixed point is called the center. A line segment joining the center to any point on the circle is called a radius.
- 30. Convex A figure is convex if every line segment drawn between any two points inside the figure lies entirely inside the figure. A figure that is not convex is called a concave figure. Convex: Concave:
- 31. Credits • Math League – Steve Conrad http://www.mathleague.com/help/geometry/ polygons.htm