The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Math Topics »

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Three Sided Pyramid Volume Question.
Replies: 2   Last Post: Nov 9, 2017 12:08 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]

Posts: 4
From: Bermuda
Registered: 11/8/17
Three Sided Pyramid Volume Question.
Posted: Nov 8, 2017 2:44 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

For the record I'm 56, so this isn't homework. :)

I've enclosed a diagram of the problem I'm working for reference.

Start with a cube. All edges are the same value. For reference, the corners of the cube are designated by numbers, the middle point of each edge is identified by a letter. Clear as mud?

I need to take away the corners and determine the volume without them. One corner is determined by lines from A -> D D -> F F -> A

Assuming each edge is 3.720, the middle point (from 1 -> D or D -> 4) is 1.860.

Finding the distance from A -> D is found by simple trig to be 2.63044

The volume of a three sided pyramid can be found with the formula V = 1/3AH
A = area of the triangle base. H = height of the pyramid.

I know A = 2.99611, but how do I find H or the height in that scenario? Once I know that I can multiply corner volume by 8 to get the volume of all eight corners and subtract it from the whole.


Imgur image here:

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.