Lesson 2 Pre-Visit A Diamond Filled with Shapes Objective: Students will be able to: Define the term polygon. Recognize different polygons evident in baseball. Draw and identify different polygons. Time Required: 1 class period Materials Needed: - Students Geometry Dictionaries started in Lesson 1 - Baseball Polygons cards (included) printed and cut out - Copies of the Defining Polygons worksheet (included) - 1 for each student - Glue sticks - Markers or crayons - Index cards (4 for each student) - 7 sheets of poster board - Label each with the name of a different polygon (square, rectangle, triangle, quadrilateral, pentagon, hexagon, and octagon) and hang them up around the room. Vocabulary: Angle - The figure formed by two lines extending from the same point Congruent - Having the same size and shape Geometry - A branch of mathematics that deals with points, lines, angles, and shapes Hexagon - A six-sided polygon Octagon An eight-sided polygon Parallel Lines moving in the same direction but always the same distance apart Pentagon - A five-sided polygon Perpendicular Lines that intersect at 90 degree angles Polygon A closed figure made up of line segments Quadrilateral - A four-sided polygon Rectangle - A quadrilateral with two pairs of congruent sides and four right angles Square - A quadrilateral with four congruent sides and four right angles Triangle - A three-sided polygon 14
Applicable Common Core State Standards: CCSS.Math.Content.3.G.A.1 Understand that shapes in different categories (e.g., rhombuses, rectangles, and others) may share attributes (e.g., having four sides), and that the shared attributes can define a larger category (e.g., quadrilaterals). Recognize rhombuses, rectangles, and squares as examples of quadrilaterals, and draw examples of quadrilaterals that do not belong to any of these subcategories. CCSS.Math.Content.4.G.A.2 Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles. CCSS.Math.Content.5.G.B.3 Understand that attributes belonging to a category of twodimensional figures also belong to all subcategories of that category. For example, all rectangles have four right angles and squares are rectangles, so all squares have four right angles. 15
Lesson 1. Introduce the term polygon and have students add this word to their Geometry Dictionaries. 2. Explain that a polygon is a plane shape (two-dimensional or flat ) with straight sides that connect. The points at which the sides connect are angles. In fact, the word polygon actually means many-angles. 3. Polygons are often named after the number of sides they have. Draw several different types of polygons on the board, and then label each, demonstrating how the number of sides gives each polygon its name. - Triangle: A three-sided polygon - Quadrilateral: A four-sided polygon - Pentagon: A five-sided polygon - Hexagon: A six-sided polygon - Octagon: An eight-sided polygon 4. Have students add each polygon to their Geometry Dictionaries. 5. Briefly discuss squares and rectangles. Both shapes are quadrilaterals. Squares have four congruent sides and four right angles. Rectangles have two congruent sides and four right angles. Review vocabulary words congruent and parallel and perpendicular. Have students add each word to their Geometry Dictionaries. 6. Introduce the activity. 16
Activity 1. First, pass around the Baseball Polygons cards (included). Have students work with a partner to identify the polygon represented by each baseball item, then sort the shapes into two piles based on the shapes geometric attributes. 2. While students are working, bring out the 7 sheets of poster board and hang them around the room. Label each with one of the polygons discussed in this lesson: square, rectangle, triangle, quadrilateral, pentagon, hexagon, and octagon. 3. Have student pairs show and tell how they sorted the Baseball Polygon cards. Review that there are many different ways that the polygons can be sorted. 4. Have students use glue sticks to attach the Baseball Polygon cards to the appropriate poster-boards. 5. Next, pass out four index cards to each student. Have students draw a different polygon from this lesson on each of these cards. 6. When students have finished their drawings, collect the cards. Mix them up and redistribute them so that each student has four cards drawn by other students. 7. Have students label each card with the correct polygon name, then sort the shapes into two piles based on the shapes geometric attributes. Then, on a separate sheet of paper, have students write down how the shapes in each pile are alike and how they are different. 8. Finally, have students attach the shapes to the appropriate poster-boards. Conclusion: To conclude this lesson and check for understanding, provide students with the Defining Polygons worksheet (included) and have students work independently to identify each shape. 17
Defining Polygons Name: Date: Instructions: 4 groups of friends want to play catch. Identify the different polygons formed by their throwing patterns. Group A Group B Tomás Tina Angela Gina John Jason Andrew Mia Group C Erika Laura Group D Juan Jenny Brooke Sasha Liam Lee Simon Tomás Mike Group A: Group B: Group C: Group D: 18
Defining Polygons Answer Key Group A: Square Group B: Rectangle Group C: Pentagon Group D: Hexagon 19
Baseball Polygons Scoreboard Home Plate 20
Pitching Rubber Pitching Screen 21
Base Pennant Batter s Box 22