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PLANE SLICE Describe the two-dimensional figures that result from slicing three-dimensional figures TABLE OF CONTENTS Vocabulary……………………………………………………………..Slide 3 Lesson A…………………………………………………………………Slide 4 Lesson B………………………………………………………………….Slide 11 Vocabulary • • • • • • • • • • • • CROSS-SECTION- THE SHAPE YOU GET WHEN CUTTING STRAIGHT ACROSS AN OBJECT PARALLEL- LINES IN A PLANE THAT DO NOT MEET PERPENDICULAR- RELATIONSHIP BETWEEN TWO LINES WHICH MEET AT A RIGHT ANGLE FACE- FLAT PLANAR SURFACE EDGE- LINE WHERE TWO SURFACES MEET VERTEX- CORNER OF AN INTERSECTION BASE- SIDE OF A PLANE FIGURE OR FACE OF A SOLID ANGLE- FIGURE FORMED BY TWO RAYS OR LINE SEGMENTS DIAGONAL- CROSSING FROM ONE CORNER TO ANOTHER PLANE- FLAT TWO-DIMENSIONAL SURFACE RECTANGULAR PRISM- A 3D SHAPE THAT HAS 6 FACES, 8 VERTICES, AND 12 EDGES RIGHT SQUARE PYRAMID- A 3D SHAPE THAT HAS 5 FACES, 5 VERTICES, AND 8 EDGES Lesson A In this lesson you will learn how to describe the cross sections of a rectangular prism by slicing at different angles. Review Rectangular Prism Plane Meet at 90˚ 3D 2D Interpreting a Perspective Drawing Looking at the prism straight on, the top face looks like a parallelogram. When the top face is straight up, you can see that it is actually a rectangle. A Cross Section is the two-dimensional shape you get when you cut a threedimensional shape with a plane. The Plane can be perpendicular or parallel. Perpendicular Planes intersect to form right angles. Parallel Planes never intersect Cutting a rectangular prism parallel to its base: The blue part is your Cross Section Cutting a rectangular prism NOT parallel to its base: The blue part is your Cross Section Cutting a rectangular prism perpendicular to its base: The blue part is your Cross Section Lesson B In this lesson you will learn how to describe the cross sections of a right square pyramid by slicing at different angles. Review Right Square Pyramid From Lesson A, recall what a plane is and how it relates to cross sections. View slide five for reference. Vertex 5 Faces Cutting a right pyramid with a plane parallel to its base: The blue part is your Cross Section Cutting a right square pyramid NOT parallel to its base: The blue part is your Cross Section The ends on the quadrilateral are different lengths because the far side is closer to the top vertex. Cutting a right square pyramid with a plane perpendicular to its base containing the vertex: Sources: http://www.youtube.com/watch?v=y8ct1mPYHUk&f eature=player_embedded http://www.youtube.com/watch?v=2mrJhslPjFw&fea ture=player_embedded