Turn on thread page Beta

The Fencing Problem - semi-circles watch

    • Thread Starter
    Offline

    0
    ReputationRep:
    Can anyone tell me if it is possible to work out how the fencing would have to be distributed to make a semi-circle (ie. how long the curved edge would be, and how long the straight edge would be)
    Offline

    2
    ReputationRep:
    (Original post by elfbadger)
    Can anyone tell me if it is possible to work out how the fencing would have to be distributed to make a semi-circle (ie. how long the curved edge would be, and how long the straight edge would be)
    The curved bit would have to be pi/2 times the length of the straight bit.

    Ben
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Ben.S.)
    The curved bit would have to be pi/2 times the length of the straight bit.

    Ben
    So in other words, with 1000 metres of fence, it would be 1000/(pi/2) to work out the length of the straight? Or does what I just said make no sense?
    Offline

    1
    ReputationRep:
    If you mean the perimeter of a semicircle:

    P=((pi)d/2)+d, where d=diameter
    • Thread Starter
    Offline

    0
    ReputationRep:
    So how would I work out the diameter from the perimeter?
    Offline

    2
    ReputationRep:
    (Original post by elfbadger)
    So in other words, with 1000 metres of fence, it would be 1000/(pi/2) to work out the length of the straight? Or does what I just said make no sense?
    The whole fence must be of length x[1+(pi/2)]. You can find the lengths of either part of a semicircle from that. So, with a 1000m fence;

    x = 1000/[1+(pi/2)]
    Straight length = x
    Curved length = (pi/2)x

    Ben
    Offline

    1
    ReputationRep:
    (Original post by XTinaA)
    If you mean the perimeter of a semicircle:

    P=((pi)d/2)+d, where d=diameter
    To get d:

    P=((pi)d/2)+d
    =d((pi)/2+1)
    d=P/(pi/2+1) (edited error, cheers Ben S)

    I think...
    • Thread Starter
    Offline

    0
    ReputationRep:
    Thanks, I got the grasp of it (eventually) from what Ben said.
    • Thread Starter
    Offline

    0
    ReputationRep:
    By the way, you're wonderful, wonderful people.
    Offline

    2
    ReputationRep:
    (Original post by XTinaA)
    To get d:

    P=((pi)d/2)+d
    =d((pi)/2+1)
    d=(pi/2+1)/P

    I think...
    You've got your division the wrong way round!

    Ben
    Offline

    1
    ReputationRep:
    (Original post by Ben.S.)
    You've got your division the wrong way round!

    Ben
    Guuh! Oh yeah. Youse know what I mean...
    • Thread Starter
    Offline

    0
    ReputationRep:
    Doesn't matter, you still know what you're talking about better than I do.
 
 
 

University open days

  • Staffordshire University
    Everything except: Midwifery, Operating Department Practice, Paramedic Undergraduate
    Sun, 21 Oct '18
  • University of Exeter
    Undergraduate Open Days - Exeter Campus Undergraduate
    Wed, 24 Oct '18
  • University of Bradford
    Faculty of Health Studies Postgraduate
    Wed, 24 Oct '18
Poll
Who is most responsible for your success at university

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.