Results 1 to 3 of 3

Thread: Triangle Building Equation

  1. #1

    Triangle Building Equation

    Hi,

    I'm looking to create a formula that will solve for side C of a triangle. There's a catch though, so it's not your everyday formula.

    Attached is a picture of what the formula needs to solve and what variables will exist.

    What makes this tricky is the 65' and 25' angle on one side of the 2'x4'. I've tried making the cuts based off the normal triangle formula but the boards end up short and not meeting flush at he peak.

    The blue dotted line is what I'm trying to solve and/or, what the true length of the board should be BEFORE the cuts are made.

    Please help! AND THANK YOU!!

    Attached Images Attached Images

  2. #2
    Elite Member
    Join Date
    Jul 2014
    Posts
    3,386
    Quote Originally Posted by kyle4rp View Post
    Hi,

    I'm looking to create a formula that will solve for side C of a triangle. There's a catch though, so it's not your everyday formula.

    Attached is a picture of what the formula needs to solve and what variables will exist.

    What makes this tricky is the 65' and 25' angle on one side of the 2'x4'. I've tried making the cuts based off the normal triangle formula but the boards end up short and not meeting flush at he peak.

    The blue dotted line is what I'm trying to solve and/or, what the true length of the board should be BEFORE the cuts are made.

    Please help! AND THANK YOU!!

    First, we will need some other dimension(s) somewhere. Possibly from the rafter midpoint to the outside top (call that A) or from the rafter midpoint to the outside edge (call that B) or ...

    Next, look at the top. That 65[tex]^{\circ}[/tex] is not the angle at the top [as I understand the image]. Rather half that (32.5[tex]^{\circ}[/tex]) is the angle on the board cut which would give a distance to the inside top (call that A') of A - [tex]\dfrac{7}{2\, cos(32.5^{\circ})}[/tex]. Remember that a '2X4' is really only 1.5X3.5. Do the same sort of thing for side associated with B. That will give you better dimensions to work with.

    If I have misread the image, please specifically state what the angles are associated with. Oh, and you will still need the A or B or ...

    -Ishuda

  3. #3
    Elite Member
    Join Date
    Feb 2004
    Location
    Ottawa, Ontario
    Posts
    16,810
    Dunno...seems to me you're asking how to cut
    the 2by4's so that they "fit" at the top, and so that
    they "fit" where they meet the perpendicular 2by4's.
    I'm just an imagination of your figment !

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •