Circle Geo (1 Viewer)

withoutaface

Premium Member
Joined
Jul 14, 2004
Messages
15,098
Gender
Male
HSC
2004
This is from a Riverview trial, I got the rest of the test out but couldn't manage part iii of this circle geometry question out. Any help would be appreciated.
Thanks,
Justin
 

withoutaface

Premium Member
Joined
Jul 14, 2004
Messages
15,098
Gender
Male
HSC
2004
ngai said:
FIVE marks?
theyre so generous
Well the other part of question 8 was worth 8 marks and it was an absolute joke in how easy it was:p
 

Constip8edSkunk

Joga Bonito
Joined
Apr 15, 2003
Messages
2,398
Location
Maroubra
Gender
Male
HSC
2003
ECD = EFD (ECFD a cyclic quad)
ECD = ABD (ABCD cyclic quad)
so ABD = EFD

ABD + GDB + DGB = pi (triangle angle sum)
Now GDB = GFB, DGB =DFB (alt.angles)
so EFD + GFB + DFB =EFG = pi
.'. E, F, G, colliniear
 

withoutaface

Premium Member
Joined
Jul 14, 2004
Messages
15,098
Gender
Male
HSC
2004
Constip8edSkunk said:
ECD = EFD (ECFD a cyclic quad)
ECD = ABD (ABCD cyclic quad)
so ABD = EFD

ABD + GDB + DGB = pi (triangle angle sum)
Now GDB = GFB, DGB =DFB (alt.angles)
so EFD + GFB + DFB =EFG = pi
.'. E, F, G, colliniear
Thanks :)
 

dawso

needmorecustomstatusspace
Joined
Feb 25, 2004
Messages
1,029
Gender
Male
HSC
2005
yeah, i cant beleive that that was worth 5 marks, but then again, in our trial, we got 1 mark in the circle geometry bit just copying the diagram, and some people didnt even pik up that easy mark, oh well, their fault
-dawso
 

CrashOveride

Active Member
Joined
Feb 18, 2004
Messages
1,488
Location
Havana
Gender
Undisclosed
HSC
2006
I concur with the previous post. Can you imagine, a mark for "copy or trace this diagram into your writing booklet". Come on, general don't have it so easy in comparison :p
 

jumb

mr jumb
Joined
Jun 24, 2004
Messages
6,184
Gender
Male
HSC
2004
dawso said:
yeah, i cant beleive that that was worth 5 marks, but then again, in our trial, we got 1 mark in the circle geometry bit just copying the diagram, and some people didnt even pik up that easy mark, oh well, their fault
-dawso
Usually they integrate it into an easy question for 1 mark. eg copy the diagram and explain why x = y.
 

Jase

Member
Joined
Mar 7, 2004
Messages
724
Location
Behind You
Gender
Male
HSC
2004
Suppose an evil dictator like neo-hitler-jesus appears and he is calling upon the world heroes to prove to him that the second tangent to three external points from a large circle is concurrent to the centre of three circles each with their centres on the tangents arbitrarily. And if you win he will promise to commit suicide and the world will be saved.

So think again before taking circle geo for granted, We could be heroes...
 

Grey Council

Legend
Joined
Oct 14, 2003
Messages
1,426
Gender
Male
HSC
2004
I've seen this question in more trials papers than ANY other circle geo question.

trust me. it's in ssoooooo many.

:-\
 

Archman

Member
Joined
Jul 29, 2003
Messages
337
Gender
Undisclosed
HSC
N/A
gordo said:
circle geometry is so stupid
wen would it ever be needed
haha well do you want to get rid of one of the few last topics in hsc maths that is non mechanical and requires some sort of deductive reasoning?
 

withoutaface

Premium Member
Joined
Jul 14, 2004
Messages
15,098
Gender
Male
HSC
2004
grimreaper said:
I disagree. Mechanics is one of the few obvious "real world" applications of the 4u course
If you want real world applications do general.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top