# UNIT 8 lesson 8.1 g7.pptx

27. May 2023
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### UNIT 8 lesson 8.1 g7.pptx

• 1. Chapter 8: Shapes and symmetry By: Eng./Teacher Wael Shnoudi
• 2. 8.1 Quadrilaterals and polygons
• 3. Objectives 01 02 03 04 Identify the symmetry of regular polygons Identify Rotational Symmetry of polygons Identify and describe the hierarchy of quadrilaterals. Know the different types of polygons
• 4. Lines of Symmetry • A line that can be drawn through a shape so that what can be see on either side is a mirror image. • It is sometimes called a Mirror Line
• 5. These shapes have one line of symmetry
• 6. These shapes have two lines of symmetry
• 7. Some shapes have more than 2 lines of symmetry Square Equilateral Triangle Circle
• 8. Rotational Symmetry A square has a rotational symmetry of order 4
• 9. Rotational Symmetry • Rotational Symmetry is how many times a shape can be rotated and fit within itself • Rotational Symmetry is how many times a shape can be rotated and look the same
• 10. Equilateral Triangle An equilateral triangle has a rotational symmetry of order 3
• 11. What is the rotational symmetry of this shape? It has to be rotated one complete turn before it fits into itself Order 1
• 12. Shapes and Symmetry
• 13. Refer to book
• 14. These figures are not polygons These figures are polygons Definition:A closed figure formed by a finite number of coplanar segments so that each segment intersects exactly two others, but only at their endpoints. Polygons
• 15. Classifications of a Polygon Regular: A polygon in which all angles are congruent and all sides are congruent That’s an equiangular equilateral polygon. Irregular: A polygon that is not regular
• 17. What is a Quadrilateral? • A quadrilateral is a two-dimensional figure with four sides and four angles. • The word part “quad” means 4 and “lateral” means sides.
• 18. Quadrilaterals in the real world
• 19. Types of Quadrilaterals Square Rectangle Trapezoid Rhombus Paralellogram
• 20. A SQUARE • A square is a quadrilateral with 4 equal sides and 4 right angles.
• 21. A RECTANGLE • A rectangle is a quadrilateral with 4 right angles. • Its opposite sides are equal and parallel.
• 22. Is a square a rectangle? REMEMBER: • A rectangle is a quadrilateral with 4 right angles. Its opposite sides are equal and parallel. • A square is a quadrilateral with 4 equal sides and 4 right angles. Rectangle?
• 23. Is a rectangle a square? REMEMBER: • A rectangle is a quadrilateral with 4 right angles. Its opposite sides are equal and parallel. • A square is a quadrilateral with 4 equal sides and 4 right angles. Square?
• 24. Determination….. • A square can also be called a rectangle because it has four right angles and its opposite sides are equal and parallel. A rectangle is NOT a square because it does not have equal sides.
• 25. A TRAPEZOID • A trapezoid is a quadrilateral that has exactly 1 pair of parallel sides.
• 26. IS THIS A TRAPEZOID? ◦ Yes, it has one set of parallel sides.
• 27. A RHOMBUS • A rhombus is a quadrilateral that has 4 equal sides. Its opposite sides are parallel.
• 28. A PARALLELOGRAM • A parallelogram is a quadrilateral that has opposite sides that are equal and parallel. • Which of the quadrilaterals we have seen are parallelograms?
• 29. Have 4 sides and 4 angles Has opposite sides that are equal and parallel. Has 1 pair of parallel sides. Has 4 right angles. Opposite sides are equal and parallel. Has 4 equal sides. Opposite sides are parallel. Has 4 equal sides and 4 right angles. What conclusions can we draw from the graphic?
• 30. A square can also be called a rhombus, a rectangle, a parallelogram, and a quadrilateral. A rectangle can also be called a parallelogram and a quadrilateral. A rhombus can also be called a parallelogram and a quadrilateral. A parallelogram can also be called a quadrilateral. A trapezoid is a quadrilateral. Have 4 sides and 4 angles Has opposite sides that are equal and parallel. Has 1 pair of parallel sides. Has 4 right angles. Opposite sides are equal and parallel. Has 4 equal sides. Opposite sides are parallel. Has 4 equal sides and 4 right angles.
• 31. Book
• 32. Book
• 33. Book
• 34. Book
• 35. Book
• 36. HW Workbook p.96-97
• 37. Book
• 38. Book
• 39. Book
• 40. Book
• 41. Book
• 42. Book
• 43. HW Workbook p.100-101
• 44. ANY QUESTIONS?