<p> Geometry – Chapter 8 Lesson Plans</p><p>Section 8.5 – Trapezoids</p><p>Enduring Understandings: The student shall be able to: 1. identify and use the properties of trapezoids and isosceles trapezoids</p><p>Standards: 11. Points, Lines and Planes Classifies triangles as acute, right, obtuse, equilateral, isosceles, scalene; and classifies polygons as regular, convex, congruent.</p><p>14. Points, Lines and Planes States and applies the triangle sum, exterior angles, and polygon angle sum theorems.</p><p>19. Congruence States and applies properties of triangles and quadrilaterals such as parallelograms, rectangles, rhombi, squares, and trapezoids.</p><p>21. Similarity Uses properties of quadrilaterals to establish and test relationships involving diagonals, angles, and lines of symmetry.</p><p>Essential Questions: What is a trapezoid? How does it fit in with the other quadrilaterals?</p><p>Warm up/Opener: </p><p>Activities: Lesson/Body: Definitions: - Make a drawing as I describe the vocabulary. A Trapezoid is a quadrilateral with exactly on pair of parallel sides. The parallel sides are called bases (so it has two bases). The non-parallel sides are called legs. Each trapezoid has two pairs of base angles. </p><p>Read Example 1.</p><p>The median of a trapezoid is the segment that joins the midpoints of its legs.</p><p>Thm 8-13: (give without proof) The median of a trapezoid is parallel to the bases, and the length of the median equals one-half the sum of the lengths of the bases.</p><p>If the legs of a trapezoid are congruent, the trapezoid is an isosceles trapezoid. Like the base angles of an isosceles triangle being equal: Thm. 8-14: Each pair of base angles in an isosceles trapezoid is congruent. Do problems 23-28</p><p>Do the Venn diagrams for the quadrilaterals we have studied in this chapter. The trapezoid has no shared characteristics with the parallelogram except that they are all quadrilaterals.</p><p>Assessments: CW WS 8.5</p><p>HW pg 337-338, # 9 - 35 odd (9)</p>