Page 2 of 2 FirstFirst 12
Results 16 to 26 of 26

Math Help - finding height and angle?

  1. #16
    Super Member
    Joined
    Oct 2008
    From
    Bristol, England
    Posts
    897
    Quote Originally Posted by scounged View Post
    12.5/24=(12.5*2)/(24*2)=25/48
    I know it's rinsed by 2 but why do you times it by 2??
    Follow Math Help Forum on Facebook and Google+

  2. #17
    Junior Member
    Joined
    Feb 2011
    Posts
    68
    Oh, that's just to get rid of the decimal in the numerator for simplicitys sake.
    Follow Math Help Forum on Facebook and Google+

  3. #18
    Super Member
    Joined
    Oct 2008
    From
    Bristol, England
    Posts
    897
    so would this mean the angle VAC is also 58.61?
    Follow Math Help Forum on Facebook and Google+

  4. #19
    Junior Member
    Joined
    Feb 2011
    Posts
    68
    Yes, I think so.
    Follow Math Help Forum on Facebook and Google+

  5. #20
    Super Member
    Joined
    Oct 2008
    From
    Bristol, England
    Posts
    897
    wouldn't you double it? because VCM if one triangle piece and VAC is double the size?
    Follow Math Help Forum on Facebook and Google+

  6. #21
    Junior Member
    Joined
    Feb 2011
    Posts
    68
    Quote Originally Posted by andyboy179 View Post
    wouldn't you double it? because VCM if one triangle piece and VAC is double the size?
    I think you're making this task more difficult than it has to be. Let's look at the pyramid from a side point of view:
    finding height and angle?-triangel.gif

    As you can see \angle(A)=\angle(VAC)=\angle(VAM)

    Notice that the angles VAC and VAM are equal. This doesn't mean that \triangle(VAC)=\triangle(VAM), which in fact is a false statement (oh, btw \angle(VAC)=\angle(VCA) and \angle(VCM)).
    Angles have nothing to do with the lengths of sides, it's a method of describing the difference in direction between two lines, regardless of the lengths.
    Follow Math Help Forum on Facebook and Google+

  7. #22
    Super Member
    Joined
    Oct 2008
    From
    Bristol, England
    Posts
    897
    VAM is 1 triangle part and VAC is 2 so why wouldn't you times 58.61 by 2??

    i can't see how VAM and VAC are equal!

    VAM=
    finding height and angle?-thiss.jpg

    VAC=

    finding height and angle?-thiss.jpg
    Follow Math Help Forum on Facebook and Google+

  8. #23
    Junior Member
    Joined
    Feb 2011
    Posts
    68
    I'm not sure if I can explain this in a great way, but I'll try.

    We need to see the difference between what an angle is and what a triangle is.
    Therefore, I will strip my previous images from the sides h and VC (also the point C), leaving us with only two lines with an angle between them:



    In this picture we have two sides (VA and AM), and one angle(VAM). Let's see what happens if we extend the side AM a bit:



    In this picture the side AM has been extended. As we can see, the angle VAM has not been affected by this change of length in AM.


    Let's now examine what happens if we have a triangle. I'll create a triangle out of my first example by adding the side VM:



    Surprisingly enough, the angle VAM remains the same.


    Let's now take the triangle VAM and extend the side AM to see what happens:



    Let's see what has changed here. The length of the side AM has changed. The length of the side VM has changed. Even the area has changed. The angle VAM however, still remains the same. It seems like the angle VAM doesn't depend on the length of the side AM.

    Let's merge the triangles and name point M in the second triangle C, and call the distance of VM h:



    In this triangle we can see that the angle VAM is equal to the angle VAC (remember that C is the point M in the second triangle). Why is that? Well, it depends on the fact that the side AM has the same direction as the side AC, despite being of a different length, and an angle measures the difference of the direction of two lines, not the difference of lengths or anything else for that matter.

    I hope that this has cleared a few things up, and has helped you understand your problem a little better.
    Follow Math Help Forum on Facebook and Google+

  9. #24
    Super Member
    Joined
    Oct 2008
    From
    Bristol, England
    Posts
    897
    Oh I think I understand now, so VAC would be 58.61?
    Follow Math Help Forum on Facebook and Google+

  10. #25
    Super Member
    Joined
    Oct 2008
    From
    Bristol, England
    Posts
    897
    Also would the height = 20.49
    Follow Math Help Forum on Facebook and Google+

  11. #26
    Junior Member
    Joined
    Feb 2011
    Posts
    68
    Yes, you're absolutely right.
    Follow Math Help Forum on Facebook and Google+

Page 2 of 2 FirstFirst 12

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: November 14th 2011, 08:23 AM
  2. Finding the Height of a cliff
    Posted in the Trigonometry Forum
    Replies: 8
    Last Post: April 11th 2010, 07:31 AM
  3. Finding height of cone
    Posted in the Geometry Forum
    Replies: 1
    Last Post: September 8th 2009, 11:52 AM
  4. Finding angle/ Double angle formula
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: May 29th 2009, 07:43 AM
  5. Replies: 2
    Last Post: March 28th 2009, 02:18 PM

Search Tags


/mathhelpforum @mathhelpforum