1 2 2 p y r a m i d s
This presentation is the property of its rightful owner.
Sponsored Links
1 / 15

1 2. 2 p y r a m i d s PowerPoint PPT Presentation


  • 39 Views
  • Uploaded on
  • Presentation posted in: General

1 2. 2 p y r a m i d s. Names of pyramids. Names are based on the shape of the pyramids base. Reference whether it is regular or not To label a pyramid you start with the vertex, and then a hyphen, and then list the vertices of the base. This pyramid is a regular pentagonal pyramid

Download Presentation

1 2. 2 p y r a m i d s

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


1 2 2 p y r a m i d s

12.2pyramids


Names of pyramids

Names of pyramids

  • Names are based on the shape of the pyramids base.

    • Reference whether it is regular or not

  • To label a pyramid you start with the vertex, and then a hyphen, and then list the vertices of the base.


1 2 2 p y r a m i d s

  • This pyramid is a regular pentagonal pyramid

  • Referred to as V-ABCDE

  • V is the vertex

  • ABCDE is the base


1 2 2 p y r a m i d s

  • The segment from the vertex perpendicular to the base is the altitude.


1 2 2 p y r a m i d s

  • The 5 faces that have V in common are the lateral faces. The edges of the

    lateral faces are called the

    lateral edges.


1 2 2 p y r a m i d s

  • Most pyramids that you will encounter are regular pyramids, with the following properties

  • Base is a regular polygon

  • All lateral edges are congruent

  • All lateral faces are congruent isosceles triangles. The height of a lateral face is called the SLANT HEIGHT of the pyramid.

  • The altitude meets the base at its center.


1 2 2 p y r a m i d s

  • Slant height


2 methods for finding the lateral area of a regular pyramid

2 methods for finding the lateral area of a regular pyramid

  • Method 1

    • Find the area of one lateral face and multiply by n (number of faces)


1 2 2 p y r a m i d s

  • Method 2

    • Theorem – the lateral area of a regular pyramid equals half the perimeter of the base times the slant height (l).

    • L.A. = ½ Pl


Find the l a

Find the L.A.


Find the l a1

Find the L.A.

  • Hint, need to find slant height

  • Probably going to need to find

    the apothem of the base.


Volume

Volume

  • The volume of a pyramid equals one third the area of the base times the height of the pyramid. (V=1/3 Bh)

    • Tip – if the base is a regular polygon then you need to use the formula A= ½ aP to find the base area.


Find the volume

Find the volume

  • Suppose this figure has base

    edges of 8 and height of 12


1 2 2 p y r a m i d s

  • Again the formulas may seem basic but there are values that we need to determine using things like special right triangles, apothems, trigonometry, isosceles triangles, etc.

  • “Mathematicians stand on each other's shoulders.”

    • Gauss

  • What one person has accomplished in mathematics is due to the many that came before them, this idea reverberates through concepts as well.


Pg 485 1 10 16 18 21 23 27

Pg. 485 1-10, 16, 18, 21, 23, 27


  • Login