PLANE SLICE
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-SECTIONTHE SHAPE YOU GET WHEN CUTTING STRAIGHT ACROSS AN OBJECT
• PARALLELLINES IN A PLANE THAT DO NOT MEET
• PERPENDICULARRELATIONSHIP BETWEEN TWO LINES WHICH MEET AT A RIGHT ANGLE
• FACEFLAT PLANAR SURFACE
• EDGELINE WHERE TWO SURFACES MEET
• VERTEXCORNER OF AN INTERSECTION
• BASESIDE OF A PLANE FIGURE OR FACE OF A SOLID
• ANGLEFIGURE FORMED BY TWO RAYS OR LINE SEGMENTS
• DIAGONALCROSSING FROM ONE CORNER TO ANOTHER
• PLANEFLAT TWO-DIMENSIONAL SURFACE
• RECTANGULAR PRISMA 3D SHAPE THAT HAS 6 FACES, 8 VERTICES, AND 12 EDGES
• RIGHT SQUARE PYRAMIDA 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
Meet at 90˚
3D
Plane
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
Vertex
5 Faces
From Lesson A, recall what a
plane is and how it relates to cross sections.
View slide five for reference.
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 ends on the quadrilateral are different lengths because the far side is closer to the top vertex.
The blue part is your Cross Section
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
