Turn on thread page Beta
    • Thread Starter
    Offline

    0
    ReputationRep:
    I have tried to do this but i just cant see how.
    show that if Angle BPA has measue "a" then angle CPD has measure "a"
    I have written equations such as "a" (which is angle APD) + BPC = 180 etc, is this the right track?
    Can someone help me please


    Edit : i know the picture is small - but if you click on it, you can see it more clearly
    • Wiki Support Team
    Offline

    14
    ReputationRep:
    Wiki Support Team
    That depends what you're allowed to assume here. Most schools would allow you to write down without proof (because it's fairly 'obvious') that angle BPA = angle CPD - if you're not allowed to write that, you might not be allowed to write that angle BPA + angle APD = 180 degrees. Nonetheless, if you know that you are allowed to write that, it's the right way forward.

    Otherwise: can you tell us what exactly you've been taught already, so that we can see how to help you?
    Offline

    11
    ReputationRep:
    (Original post by Hrov)
    I have tried to do this but i just cant see how.
    show that if Angle BPA has measue "a" then angle CPD has measure "a"
    I have written equations such as "a" (which is angle APD) + BPC = 180 etc, is this the right track?
    Can someone help me please


    Edit : i know the picture is small - but if you click on it, you can see it more clearly
    the general idea is right..
    angle APD+angle BPC=180
    similarly angle BPC+ and angle CPd= 180
    Can you see what to do next?
    To show that angle APD=angle CPd
    • TSR Group Staff
    Offline

    20
    ReputationRep:
    TSR Group Staff
    Basically yes. If you look at two angles on line 2 and the same on line 1 you can get a pair of simultaneous equations:

    \rm{BPA} + \rm{APD} = 180^o
    \rm{CPD} + \rm{APD} = 180^o

    After that, it's merely a case of solving those and reaching the conclusion.
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by generalebriety)
    That depends what you're allowed to assume here. Most schools would allow you to write down without proof (because it's fairly 'obvious') that angle BPA = angle CPD - if you're not allowed to write that, you might not be allowed to write that angle BPA + angle APD = 180 degrees. Nonetheless, if you know that you are allowed to write that, it's the right way forward.

    Otherwise: can you tell us what exactly you've been taught already, so that we can see how to help you?
    Thanks for the quick reply
    Its the first lesson of applied maths at uni,

    We have been learning about euclids 5th axiom before now,

    the exact question is "for the figure below show that if angle BPA has measure 'theta' then angle CPD has measure 'theta'
    • Thread Starter
    Offline

    0
    ReputationRep:
    everyone ignore me i'm being stupid , i might need your help late though
    Offline

    0
    ReputationRep:
    (Original post by Hrov)
    I have tried to do this but i just cant see how.
    show that if Angle BPA has measue "a" then angle CPD has measure "a"
    I have written equations such as "a" (which is angle APD) + BPC = 180 etc, is this the right track?
    Can someone help me please


    Edit : i know the picture is small - but if you click on it, you can see it more clearly
    well they are vertically opposite angles.... so they are equal....
    but in case you are not allowed without proof....
    BPA+APD = 180
    CPD+APD = 180
    and subtract the two equations....
    • Wiki Support Team
    Offline

    14
    ReputationRep:
    Wiki Support Team
    (Original post by Hrov)
    Thanks for the quick reply
    Its the first lesson of applied maths at uni,

    We have been learning about euclids 5th axiom before now,

    the exact question is "for the figure below show that if angle BPA has measure 'theta' then angle CPD has measure 'theta'
    Oh. Well, you're going to have to tell us what axioms you're working from. :confused: Otherwise we'll never know.
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by generalebriety)
    Oh. Well, you're going to have to tell us what axioms you're working from. :confused: Otherwise we'll never know.
    im not sure but i think that we can only assume that a straight line is 180 degrees, and that if 2 parallel line bisect the same line, then certain angles will have to be the same to ensure that the lineS never meet, (PARALLEL)

    . Can you help me with this i dont actually know where to start. (i tried to extend lines etc but i cant see what to do)


    Show that if line1 is parrallel to line2 then a = b+c - 180
    • Wiki Support Team
    Offline

    14
    ReputationRep:
    Wiki Support Team
    Extend line 1 and the diagonal line forming angle a so that they meet. You should know that the acute angle they meet in is a, and the other two in that triangle are 180-b and 180-c. But angles in a triangle need to add up to 180...
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by generalebriety)
    Extend line 1 and the diagonal line forming angle a so that they meet. You should know that the acute angle they meet in is a, and the other two in that triangle are 180-b and 180-c. But angles in a triangle need to add up to 180...
    thanks a lot, i would rep you but it is worthless :p:
    Is there a quick way to prove that the acute angle is "a"? (just to be safe)
    • Wiki Support Team
    Offline

    14
    ReputationRep:
    Wiki Support Team
    (Original post by Hrov)
    thanks a lot, i would rep you but it is worthless :p:
    Is there a quick way to prove that the acute angle is "a"? (just to be safe)
    I don't know, you still haven't told me what axioms you're using, so really I'm just guessing. And if you don't know what axioms you're using then so are you. But if the guesses you made a couple of posts ago are correct, then it's because line 1 and line 2 are parallel and cut the same line.
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 11, 2009

University open days

  • University of Bradford
    All faculties Undergraduate
    Wed, 21 Nov '18
  • Buckinghamshire New University
    All Faculties Postgraduate
    Wed, 21 Nov '18
  • Heriot-Watt University
    All Schools Postgraduate
    Wed, 21 Nov '18
Poll
Black Friday: Yay or Nay?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Equations

Best calculators for A level Maths

Tips on which model to get

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

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.