ATAR Notes: Forum
VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Specialist Mathematics => Topic started by: wildareal on July 03, 2010, 04:26:32 pm
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Hi Could someone please tell me how you would do Questions 5 and 6 of this paper on the topic of Circle Geometry. Much Appreciated. :)
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5a) use <DAC = <DBC
also, <AXP = <QXC
from here it's a matter of adding values to make sure the triangles add to 180
I just let x=<QBX and went from there
5b) just focus on the triangle BXC. using previous answer, we know BQX is an isosceles triangle and therefore XQ = BQ, then prove that <QXC = <QCX by adding angles to 180, this proves that it is also an isosceles triangle with CQ = XQ = BQ
6a) FAC is an equilateral triangle, ie. all angles are 60
6b) FOC is half that triangle, FC by pythag is sqrt(8), from before <OCF = 60, use sin(60) = FO/FC
6c) I didn't know this: http://math.about.com/od/formulas/ss/surfaceareavol_2.htm
r=2, s is the hypotenuse of a right angled triangle of sides 1m and 2m ie. sqrt(5)
Hope this helps!