Mathematics: Post your doubts here!

[sj0007]

What does it mean by "...which are equidistant from the lines AC and BD"
And I thought it was angle bisectors of the four angles in the middle.
If it was the perpendicular bisector of AC and BD, it gives a weird looking answer.
HELPPPPPP :\

a locus of two intersecting lines is their perpendicular bisector of the two
and i do admit the diagram is very weird........but it is correct.....

 

[sj0007]

Need help with bearing question , find them really hard.
http://papers.xtremepapers.com/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_s05_qp_2.pdf
Question 20.
Thanks.

part a is 360 - (65+63) ....... u get 65 like dis 180-115.....i hope u understand from my vague explanation...

 

[Faaiz Haque]

part a is 360 - (65+63) ....... u get 65 like dis 180-115.....i hope u understand from my vague explanation...

Not really thanks anyways, can someone else help with an explanation too ,not just the solution. Also part b) thanks.

 

[notnek01]

Need help with bearing question , find them really hard.
http://papers.xtremepapers.com/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_s05_qp_2.pdf
Question 20.
Thanks.

The two north lines form part of a parallelogram with the line AG so the angle between A, G and north must be 180-115 = 65.

So the bearing G->W is 360 - 65 - 63 = 232

Is this OK? See if you can do (b) yourself now.

 

[sj0007]

The two north lines form part of a parallelogram with the line AG so the angle between A, G and north must be 180-115 = 65.

So the bearing G->W is 360 - 65 - 63 = 232

Is this OK? See if you can do (b) yourself now.

dude u explained way better..........keep it up!!!

 

[notnek01]

its pretty easy its just the perpendicular bisector of AC and BD...

No it's not. The locus equidistant from two intersecting lines is the two angle bisectors.

 

[sj0007]

Not really thanks anyways, can someone else help with an explanation too ,not just the solution. Also part b) thanks.

In part b use sine rule to find angle WAG......the add this angle to 115......as this would be the total clockwise angle from the North.....i hope it was helpfull!!

 

[Faaiz Haque]

In part b use sine rule to find angle WAG......the add this angle to 115......as this would be the total clockwise angle from the North.....i hope it was helpfull!!

Thanks I get part b) . Can you explain part A) Still confused about that

 

[sj0007]

Thanks I get part b) . Can you explain part A) Still confused about that

w8 for 2 min i'll give u good solution

 

[sj0007]

he two north lines form part of a parallelogram with the line AG so the angle between A, G and north must be 180-115 = 65.

So the bearing G->W is 360 - 65 - 63 = 232..............mayb the pic is helpful

 

[Faaiz Haque]

he two north lines form part of a parallelogram with the line AG so the angle between A, G and north must be 180-115 = 65.

So the bearing G->W is 360 - 65 - 63 = 232..............mayb the pic is helpful

Thank you so much.

 

[sj0007]

Thank you so much.

ur welcum.... i hope now u understand

 

[weirdoatlarge77]

Thank you so much for your reply! Can't thank you enough!
I have a question about map scales though, I don't quite seem to understand whether it's km to cm or are the scales all cm? ( with regards to question 15 , 0580/21/M/J/12)
Your help will be greatly appreciated! Thank you again!

 

[notnek01]

Thank you so much for your reply! Can't thank you enough!
I have a question about map scales though, I don't quite seem to understand whether it's km to cm or are the scales all cm? ( with regards to question 15 , 0580/21/M/J/12)
Your help will be greatly appreciated! Thank you again!

1 : 500,000: This means that the actual distance is 500,000 times larger than the map distance. You can put any units in the ratio and it's still correct (as long as both units are the same).

E.g. 1cm : 500,000 cm

or 1km : 500,000 km

These all mean the same thing. Does this help?

 

[sj0007]

1 : 500,000: This means that the actual distance is 500,000 times larger than the map distance. You can put any units in the ratio and it's still correct (as long as both units are the same).

E.g. 1cm : 500,000 cm

or 1km : 500,000 km

These all mean the same thing. Does this help?

yeah exactly.....

 

[weirdoatlarge77]

Thank you so much notnek101! I get it Oh, and could you explain "The locus equidistant from two intersecting lines is the two angle bisectors."
Don't really get it :/

 

[weirdoatlarge77]

Wait I actually don't get the scales
Could anyone just solve this question :
The scale of a map is 1:500000.
(a) The actual distance between two towns is 172km.
Calculate the distance, in centimetres, between the towns on the map.

Thank you!

 

[weirdoatlarge77]

Wait I actually don't get the scales
Could anyone just solve this question :
The scale of a map is 1:500000.
(a) The actual distance between two towns is 172km.
Calculate the distance, in centimetres, between the towns on the map.

Thank you!

The answer is 34.4

 

[sj0007]

Thank you so much notnek101! I get it Oh, and could you explain "The locus equidistant from two intersecting lines is the two angle bisectors."
Don't really get it :/

i am so sorry i wuz wrong u hav 2 make d angle bisector not perp. bisector..once again i am truly sorry

 

[notnek01]

Thank you so much notnek101! I get it Oh, and could you explain "The locus equidistant from two intersecting lines is the two angle bisectors."
Don't really get it :/

This is quite hard to explain on a forum:

If two lines AB and BC start from the same point (B) then the locus equidistant from AB and BC is the angle bisector of angle ABC. Do you understand this? It's a standard locus that you need to know.

When two lines intersect at a point, you have four sets of meeting lines (as talked about above). So you need to bisect four angles. Since two of the angles are opposite each other, you only really need to bisect two angles.

If this doesn't make sense, you may need to look in your textbook/online or have your teacher explain it to you.