FL State Adoption Bid #3704 Student Edition Eureka Math Geometry Modules 3,4, 5 Special thanks go to the GordRn A. Cain Center and to the Department of Mathematics at Louisiana State University for their support in the development of Eureka Math. For a free Eureka Math Teacher Resource Pack, Parent Tip Sheets, and more please visit www.Eureka.tools Published by WKHQRQSURILWGreat Minds Copyright © 2015 Great Minds. No part of this work may be reproduced, sold, or commercialized, in whole or in part, without written permission from Great Minds. Non-commercial use is licensed pursuant to a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 license; for more information, go to http://greatminds.net/maps/math/copyright. “Great Minds” and “Eureka Math” are registered trademarks of Great Minds. Printed in the U.S.A. This book may be purchased from the publisher at eureka-math.org 10 9 8 7 6 5 4 3 2 1 ISBN 978-1-63255-328-7 ^dKZzK&&hEd/KE^ Lesson 1 M3 GEOMETRY Lesson 1: What Is Area? Classwork Exploratory Challenge 1 a. What is area? b. What is the area of the rectangle below whose side lengths measure ͵ units by ͷ units? ଷ ହ c. What is the area of the ൈ rectangle below? ସ ଷ Lesson 1: What Is Area? S.1 ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 1 M3 GEOMETRY Exploratory Challenge 2 a. What is the area of the rectangle below whose side lengths measure ξ͵ units by ξʹ units? Use the unit squares on the graph to guide your approximation. Explain how you determined your answer. b. Is your answer precise? S.2 Lesson 1: What Is Area? ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 1 M3 GEOMETRY Discussion Use Figures 1, 2, and 3 to find upper and lower approximations of the given rectangle. Figure 1 Figure 2 Lesson 1: What Is Area? S.3 ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 1 M3 GEOMETRY Figure 3 Lower Approximations Less than ξʹ Less than ξ͵ Less than or equal to ܣ ͳ ͳ ͳ ൈ ͳ ൌ ͳǤ͹ ൈ ͳǤ͹ ൌ ͳǤͶͳ ͳǤͶͳ ൈ ൌ ͳǤͶͳͶ ͳǤ͹͵ʹ ͳǤͶͳͶ ൈ ͳǤ͹͵ʹ ൌ ͳǤͶͳͶʹ ͳǤ͹͵ʹͲ ͳǤͶͳͶʹ ൈ ͳǤ͹͵ʹͲ ൌ ʹǤͶͶͻ᩺͵ͶͶ ൌ ʹǤͶͶͻ᩺Ͷͺʹ᩺Ͷ͵Ͳ᩺ͷ ͳǤͶͳͶ᩺ʹͳ͵ ͳǤ͹͵ʹ᩺ͲͷͲ ͳǤͶͳͶ᩺ʹͳ͵ ൈ ͳǤ͹͵ʹ᩺ͲͷͲ ൌ ʹǤͶͶͻ᩺Ͷͺ͹᩺͸ʹ͸᩺͸ͷ S.4 Lesson 1: What Is Area? ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 1 M3 GEOMETRY Upper Approximations Greater than ξʹ Greater than ξ͵ Greater than or equal to ܣ ʹ ʹ ʹ ൈ ʹ ൌ Ͷ ͳǤͷ ͳǤͺ ͳǤͷ ൈ ͳǤͺ ൌ ͳǤͶʹ ͳǤ͹Ͷ ͳǤͶʹ ൈ ͳǤ͹Ͷ ൌ ʹǤͶ͹Ͳͺ ͳǤ͹͵͵ ൈ ͳǤ͹͵͵ ൌ ͳǤͶͳͶ͵ ͳǤ͹͵ʹͳ ͳǤͶͳͶ͵ ൈ ͳǤ͹͵ʹͳ ൌ ʹǤͶͶͻ᩺͹Ͳͻ᩺Ͳ͵ ͳǤͶͳͶʹʹ ͳǤ͹͵ʹͲ͸ ͳǤͶͳͶʹʹ ൈ ͳǤ͹͵ʹͲ͸ ൌ ʹǤͶͶͻ᩺ͷͳ͵᩺ͺͻ͵᩺ʹ ൌ ʹǤͶͶͻ᩺ͶͻͲ᩺͹͹ʹ᩺ͻͳͶ Discussion If it takes one can of paint to cover a unit square in the coordinate plane, how many cans of paint are needed to paint the region within the curved figure? Lesson 1: What Is Area? S.5 ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 1 M3 GEOMETRY Problem Set ଵହ ͳ 1. Use the following picture to explain why is the same as ͳ . ଵଶ Ͷ 2. Figures 1 and 2 below show two polygonal regions used to approximate the area of the region inside an ellipse and .above the ݔ-axis Figure 1 Figure 2 a. Which polygonal region has a greater area? Explain your reasoning. b. Which, if either, of the polygonal regions do you believe is closer in area to the region inside the ellipse and ?above the ݔ-axis 3. Figures 1 and 2 below show two polygonal regions used to approximate the area of the region inside a parabola and .above the ݔ-axis a. Use the shaded polygonal region in Figure 1 to give a lower estimate of the area ܽ under the curve and above .the ݔ-axis .b. Use the shaded polygonal region to give an upper estimate of the area ܽ under the curve and above the ݔ-axis c. Use (a) and (b) to give an average estimate of the area ܽ. S.6 Lesson 1: What Is Area? ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 1 M3 GEOMETRY ଵ 4. Problem 4 is an extension of Problem 3. Using the diagram, draw grid lines to represent each unit. ଶ a. What do the new grid lines divide each unit square into? b. Use the squares described in part (a) to determine a lower estimate of area ܽ in the diagram. c. Use the squares described in part (a) to determine an upper estimate of area ܽ in the diagram. d. Calculate an average estimate of the area under the curve and above the ݔ-axis based on your upper and lower estimates in parts (b) and (c). e. Do you think your average estimate in Problem 4 is more or less precise than your estimate from Problem 3? Explain. Lesson 1: What Is Area? S.7 ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ This page intentionally left blank S.8 ^dKZzK&&hEd/KE^ Lesson 2 M3 GEOMETRY Lesson 2: Properties of Area Classwork Exploratory Challenge/Exercises 1–4 1. Two congruent triangles are shown below. a. Calculate the area of each triangle. b. Circle the transformations that, if applied to the first triangle, would always result in a new triangle with the same area: Translation Rotation Dilation Reflection c. Explain your answer to part (b). Lesson 2: Properties of Area S.9 ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 2 M3 GEOMETRY 2. a. Calculate the area of the shaded figure below. b. Explain how you determined the area of the figure. 3. Two triangles ᇞܣܤܥ and ᇞܦܧܨ are shown below. The two triangles overlap forming ᇞܦܩܥ. a. The base of figure ܣܤܩܧܨ is composed of segments of the following lengths: ܣܦ ൌͶ, ܦܥ ൌ͵, and ܥܨ ൌʹ. Calculate the area of the figure ܣܤܩܧܨ. S.10 Lesson 2: Properties of Area ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 2 M3 GEOMETRY b. Explain how you determined the area of the figure. 4. A rectangle with dimensions ʹͳǤ͸ ൈ ͳʹ has a right triangle with a base ͻǤ͸ and a height of ͹Ǥʹ cut out of the rectangle. a. Find the area of the shaded region. b. Explain how you determined the area of the shaded region. Lesson 2: Properties of Area S.11 ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 2 M3 GEOMETRY Lesson Summary SET (description): A set is a well-defined collection of objects called elements or members of the set. indicates ܤكܣ The notation .ܤ is also an element of ܣ if every element of ܤ is a subset of a set ܣ SUBSET: A set that the set ܣ is a subset of set ܤ. UNION: The union of ܣ and ܤ is the set of all objects that are either elements of ܣ or of ܤ, or of both. The union is .ܤ׫ܣ denoted INTERSECTION: The intersection of ܣ and ܤ is the set of all objects that are elements of ܣ and also elements of ܤ. The .ܤתܣ intersection is denoted Problem Set 1. Two squares with side length ͷ meet at a vertex and together with segment ܣܤ form a triangle with base ͸ as shown. Find the area of the shaded region. 2. If two ʹൈʹ square regions ܵͳ and ܵʹ meet at midpoints of sides as .ʹshown, find the area of the square region, ܵͳ ׫ܵ S.12 Lesson 2: Properties of Area ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ ^dKZzK&&hEd/KE^ Lesson 2 M3 GEOMETRY 3. The figure shown is composed of a semicircle and a non-overlapping equilateral triangle, and contains a hole that is also composed of a semicircle and a non-overlapping equilateral triangle. If the radius of ଵ the larger semicircle is ͺ, and the radius of the smaller semicircle is ଷ that of the larger semicircle, find the area of the figure. 4. Two square regions ܣ and ܤ each have ሺͺሻ. One vertex of square ܤ is ܤתܣ and ܤ׫ܣ Can you find the area of .ܣ the center point of square without any further information? What are the possible areas? 5. Four congruent right triangles with leg lengths ܽ and ܾ and hypotenuse length ܿ are used to enclose the green region in Figure 1 with a square and then are rearranged inside the square leaving the green region in Figure 2. a. Use Property 4 to explain why the green region in Figure 1 has the same area as the green region in Figure 2. b. Show that the green region in Figure 1 is a square, and compute its area. c. Show that the green region in Figure 2 is the union of two non-overlapping squares, and compute its area. d. How does this prove the Pythagorean theorem? Lesson 2: Properties of Area S.13 ΞϮϬϭϱ'ƌĞĂƚDŝŶĚƐ͘ĞƵƌĞŬĂͲŵĂƚŚ͘ŽƌŐ 'KͲDϯͲ^ͲϮͲϭ͘ϯ͘ϬͲϭϬ͘ϮϬϭϱ This page intentionally left blank S.14 ^dKZzK&&hEd/KE^ Lesson 3 M3 GEOMETRY Lesson 3: The Scaling Principle for Area Classwork Exploratory Challenge Complete parts (i)–(iii) of the table for each of the figures in questions (a)–(d): (i) Determine the area of the figure (pre- image), (ii) determine the scaled dimensions of the figure based on the provided scale factor, and (iii) determine the area of the dilated figure. Then, answer the question that follows. In the final column of the table, find the value of the ratio of the area of the similar figure to the area of the original figure. (i) (ii) (iii) Scale Ratio of Areas Area of Original Dimensions of Area of Similar ܉܍ܚۯ ǣ ܉܍ܚۯ Factor Figure Similar Figure Figure ܛܑܕܑܔ܉ܚ ܗܚܑ܏ܑܖ܉ܔ a.