Results 1 to 10 of 10

Math Help - apply complex mathematical concepts to building and constructions principle

  1. #1
    Newbie
    Joined
    Dec 2009
    Posts
    5

    apply complex mathematical concepts to building and constructions principle

    Hi, i urgently need help with this subject, i need to complete it for a course i am wanting to enrol in, but maths wasn't for me, now i am stuck. i need help with this question,

    Find the area of the triangle with the lengths 2.87 m, 3.69 m and 4.58 m
    565 mm, 823 mm and 1.08 m

    i have no idea how to do this,

    can someone please help me.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,786
    Thanks
    1570
    Quote Originally Posted by seran View Post
    Hi, i urgently need help with this subject, i need to complete it for a course i am wanting to enrol in, but maths wasn't for me, now i am stuck. i need help with this question,

    Find the area of the triangle with the lengths 2.87 m, 3.69 m and 4.58 m
    565 mm, 823 mm and 1.08 m

    i have no idea how to do this,

    can someone please help me.
    Use Heron's Formula.

    If a, b, c are the sides of the triangle, let s be the semi-perimeter. I.e. s = \frac{a + b + c}{2}.

    Then the Area is

    A = \sqrt{s(s - a)(s - b)(s - c)}.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Dec 2009
    Posts
    5
    sorry ur going to think im pretty stupid, i did say im hopless in mtahs, but where did u get the 2 and s from???

    you've lost me sorry
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,786
    Thanks
    1570
    Follow the instructions I gave you.

    Call the three sides of your triangle a, b, c.

    Then work out the semiperimeter:

    s = \frac{a + b + c}{2}.


    Then work out the Area

    A = \sqrt{s(s - a)(s - b)(s - c)}.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,860
    Thanks
    742
    Hello, seran!

    If you can't handle Heron's Formula,
    . . then you must know some Trigonometry.


    Find the area of the triangle with the lengths 2.87 m, 3.69 m and 4.58 m

    565 mm, 823 mm and 1.08 m .
    What are these?
    We have a triangle:
    Code:
                C
                o
               *  *
           b  *     *  a
             *        *
            *           *
           *              *
        A *  *  *  *  *  *  * B
                   c
    We are given: . \begin{array}{ccc}a &=& 2.87 \\ b &=& 3.69 \\ c &=& 4.58 \end{array}


    We can find angle A with: . \cos A \:=\:\frac{b^2+c^2 - a^2}{2bc}

    Then the area is: . \tfrac{1}{2}bc\sin A


    If all this is meaningless to you,
    and you're really "hopless in math",
    . . . . just skip the problem.

    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1
    Hi seran,

    If you need this subject for a course you want to enroll in,
    why is this topic important for the course ?

    Will you have difficulty on the course without it ?
    Try the question, you might be surprised how easy it can get.

    As Soroban showed,

    If you have the 3 sides of a triangle,
    you can find any angle using the Law of Cosines, or Cosine Rule


    Then,
    you can find the area of a triangle if you have all 3 dimensions at any of the 3 corners,
    using the triangle area formula, for a triangle for which you are not given the perpendicular height and base.
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Dec 2009
    Posts
    5
    I want to study architecture and one of the pre-req is that i have to have completed maths in year 12, which i never did, so the course i will be doing am assuming won't involve algebra etc, just measure etc. i haven't done maths since 1993, thats 17 years. so really nothing is sinking in and is getting really depresed cause i feel so stupid. thanks all for your helps.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Newbie
    Joined
    Dec 2009
    Posts
    5
    Hi, thank you all, ooo i feel stupid, no i don't know trig, like i mentioned i did maths about 17 years ago, and really never paid attention to the teacher because maths was never my best friend. so i didnt take it up in year 12 either. Now i want to study from home architecture and one of the pre-req is that i have to have completed maths in year 12. Or to do this subject, i think i need a private tutor.
    Follow Math Help Forum on Facebook and Google+

  9. #9
    No one in Particular VonNemo19's Avatar
    Joined
    Apr 2009
    From
    Detroit, MI
    Posts
    1,823
    Quote Originally Posted by seran View Post
    I want to study architecture and one of the pre-req is that i have to have completed maths in year 12, which i never did, so the course i will be doing am assuming won't involve algebra etc, just measure etc. i haven't done maths since 1993, thats 17 years. so really nothing is sinking in and is getting really depresed cause i feel so stupid. thanks all for your helps.
    You're in for a suprise! You're gonna need a lot of math there, buddy!

    Check it out.

    Architecture Degree Program Requirements
    Follow Math Help Forum on Facebook and Google+

  10. #10
    Newbie
    Joined
    Dec 2009
    Posts
    5
    ooo, know i feel even worse, gota get a tutor, thnax for that,
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Prove by Principle of Mathematical Induction
    Posted in the Number Theory Forum
    Replies: 3
    Last Post: August 11th 2011, 12:52 AM
  2. Replies: 3
    Last Post: August 8th 2010, 09:29 PM
  3. Replies: 10
    Last Post: June 29th 2010, 01:10 PM
  4. Complex Analysis-Maximum Principle
    Posted in the Advanced Math Topics Forum
    Replies: 2
    Last Post: March 8th 2010, 08:48 AM
  5. Principle of mathematical induction
    Posted in the Differential Geometry Forum
    Replies: 1
    Last Post: October 19th 2009, 03:03 PM

Search Tags


/mathhelpforum @mathhelpforum