3 VocabularyCROSS-SECTION- THE SHAPE YOU GET WHEN CUTTING STRAIGHT ACROSS AN OBJECTPARALLEL- LINES IN A PLANE THAT DO NOT MEETPERPENDICULAR- RELATIONSHIP BETWEEN TWO LINES WHICH MEET AT A RIGHT ANGLEFACE- FLAT PLANAR SURFACEEDGE- LINE WHERE TWO SURFACES MEETVERTEX- CORNER OF AN INTERSECTIONBASE- SIDE OF A PLANE FIGURE OR FACE OF A SOLIDANGLE- FIGURE FORMED BY TWO RAYS OR LINE SEGMENTSDIAGONAL- CROSSING FROM ONE CORNER TO ANOTHERPLANE- FLAT TWO-DIMENSIONAL SURFACERECTANGULAR PRISM- A 3D SHAPE THAT HAS 6 FACES, 8 VERTICES, AND 12 EDGESRIGHT SQUARE PYRAMID- A 3D SHAPE THAT HAS 5 FACES, 5 VERTICES, AND 8 EDGES
4 Lesson AIn this lesson you will learn how to describe the cross sections of a rectangular prism by slicing at different angles.
5 Review 3D 2D Rectangular Prism Plane Meet at 90˚ Infinitely Tall Six FacesInfinitely Long2D
6 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.
7 The Plane can be perpendicular or parallel. A Cross Section is the two-dimensional shape you get when you cut a three-dimensional shape with a plane.The Plane can be perpendicular or parallel.Perpendicular Planes intersect to form right angles.Parallel Planes never intersect
8 Cutting a rectangular prism parallel to its base: The blue part is your Cross Section
9 Cutting a rectangular prism NOT parallel to its base: The blue part is your Cross Section
10 Cutting a rectangular prism perpendicular to its base: The blue part is your Cross Section
11 Lesson BIn this lesson you will learn how to describe the cross sections of a right square pyramid by slicing at different angles.
12 ReviewRight Square PyramidFrom Lesson A, recall what a plane is and how it relates to cross sections. View slide five for reference.Vertex5 Faces
13 Cutting a right pyramid with a plane parallel to its base: The blue part is your Cross Section
14 Cutting a right square pyramid NOT parallel to its base: The blue part is your Cross SectionThe ends on the quadrilateral are different lengths because the far side is closer to the top vertex.
15 Cutting a right square pyramid with a plane perpendicular to its base containing the vertex: