2012 Year 9 &10 Mathematics Marathon (5 Viewers)

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

I dont understand this - many times you have to get it wrong to learn. You cant win if you dont play the game. This thread is the place to make mistakes.

Yeah but everyone else such as kaze and kev already know it and like are already looking into other ways to solve it whilst I haven't even gotten the easy way... makes me look dumb.

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

Okay let me try

 

[kazemagic]

? how can you use the sine rule to prove that the angles are equal?

like i only thought you used the rule to find a certain side or angle... damn all that r0te.

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

So the imaginary perpendicular line that bisects BC from A I shall call AD. Now, RHS is Right Angle, Hypotenuse and Side.

In Triangle ADC,

Angle ADC is a right angle at 90 degrees (since AD bisects BC)
AC is the hypotenuse
DC is the side

????

WTF

 

[kazemagic]

oh... draw a parallel line to BC
edit nvm

 

[theind1996]

View attachment 26354

Beautiful.

 

[Fawun]

View attachment 26354

How in the world is siny/ac? shouldn't it be over AB since it's opposite...

 

[kev-]

LOL, I don't know if this is valid or not, and it's not elegant but i'll still post it up.


so a=c and b=d, diagonals bisect the angles
a=d and b=c, parallel lines.
so a=b and d=c.

 

[kazemagic]

How in the world is siny/ac? shouldn't it be over AB since it's opposite...

AB=AC given in the question m8

 

[SpiralFlex]

 

[SpiralFlex]

I better draw a diagram to make clear.

 

[ganji]

dat elegance

 

[SpiralFlex]

Diagram drawn. <3 LaTeXDraw

 

[Fawun]

stop confusing me even more kient

 

[SpiralFlex]

stop confusing me even more kient

Fine. What question would you like next?

 

[deswa1]

@Fawun- do you know circle geometry? If so, there's a nice question that Carrot showed me that you could try (though it could be too difficult...)

 

[enoilgam]

stop confusing me even more kient

Well, what about my question, you think of anything?

 

[kazemagic]

Diagram drawn. <3 LaTeXDraw

theres no pic
edit nvm

 

[SpiralFlex]

@Fawun- do you know circle geometry? If so, there's a nice question that Carrot showed me that you could try (though it could be too difficult...)

I believe in young Fawn.

 

[Fawun]

I believe in young Fawn.

You shouldn't.

Well, what about my question, you think of anything?

Nope. I can't even do Spirals question let alone yours LOL

@Fawun- do you know circle geometry? If so, there's a nice question that Carrot showed me that you could try (though it could be too difficult...)

Yeah I know circle geo