Perpendicular bisector - what?!

[ivrytwr3]

Got my maths paper 3 coming up and upon doing past papers i nealry always see perpendicular bisectors.  Unfortunately i have not covered these!!!  How do you do them?

As an example there is an example on May/Jun 2006 paper 3 0580/03 0581/03 question 9 (anyone want to post the finished page here?!

[Vin]

from next on post ur doubt here ..

https://studentforums.biz/index.php/topic,7086.705.html

i'll see what i can do gimme some time ..

[Vin]

sorry for the delay ..

For perpendicular bisector ( | ) symbol .. is basically dividing a line segment to perfect half ..
In the first attachment place the rounder on one end and approx. half cut an arc on both sides .. same for the other side which should intersect .. carefully draw a line joining the arcs ..

[Vin]

9 a) i) measure AC and multiply by 10
For these type of sums don’t worry if your answers doesn’t match the markscheme because the printout wich u hav may not according the pdf size .. ju do ur calculation properly
ii) measure ACB with the protactor placed on line AC at point C .. and counting from 180 to whatever the angle is .. (no worries if u hav another method)

b) construct an angle bisector .. same as prep. Bisector but bisecting the angle A
for this u need to place the rounder at A and cut two arcs on AC and AB .. place the rounder at x and y and cut 2 arcs intersecting outside CB .. this is angle bisector ..

pls ask if any doubt ..

[ivrytwr3]

ok, that's great and thanks for your help, but still a bit stuck!

I can see how you did the A - BC fenceline, but where is the compass/ruler placed to give you the w - z line?  Question 9 c

Sorry    

[Vin]

oh sorry i forgot to mention that .. at CA ..

[astarmathsandphysics]

There is a page on my website will try and find a link

[astarmathsandphysics]

Will post a link now

[astarmathsandphysics]

http://www.astarmathsandphysics.com/o_level_maths_notes/o_level_maths_notes_constructions_bisecting_angles_and_lines.html

[Vin]

thank u sir .. you've got better pictures ..

[ivrytwr3]

I am destined to fail!  I still cannot see how you did the perpendicular bisector of the side AC!!

But thanks anyway!

[Vin]

Havnt ur maths teacher taught u locus ?? its very essential .. being a member of SF .. u cannot FAIL !! wat country r u By the way ..

i hav attached one .. i hav made some additional "rounders" .. hope u get this ..

[ivrytwr3]

from UK and no, no studying of locus. 

I understand 9b i and ii, but i still do not understand c.

On i and ii, i place the rounders on angle A and mark AC and AB, then using these marks get my X to make the locus point.

So where do i place my rounders for 9c?

(thanks for trying!!)

[Vin]

UK .. i see London ?? why dont u take tuition from astar .. =P

For this you hav to place the compass twice  .. once on A and the other time on C .. take enough measurement so tht u can make X somewhere in the middle of the diagram .. look at the attached file again..

[ivrytwr3]

you mean once on A and once on C  Because if you mean C, then i've got it and thank you very much!