E maths - trigo ratio

• bonkysleuth

  12 Oct 08, 19:56

  In triangle ABC, AB =5cm and angle BAC = 36 deg. Find the possible length(s) of BC such that the number of possible triangles ABCs that can be formed is

   

  (a) 2

  (b) 1

  (c) 0

   

  I don't get what the question is trying to say really. So, please help. :)

• Ahm97sic

  12 Oct 08, 21:25

  Hi bonkysleuth,

  This question asks about the ambiguous cases of a triangle. This topic is no longer in the E.Maths syllabus and it appears only in the 70s and early 80s "O" level exam.

  By the way, the answer is

  (1)   For two triangles, BC  < 5 cm

  (2)   For one triangle, BC > 5 cm

  (3)   For zero triangle, BC < 3 cm

  Thank you for your kind attention.

  Regards,

  ahm97sic

   

• SBS n SMRT

  13 Oct 08, 10:55

  Originally posted by Ahm97sic:

  Hi bonkysleuth,

  This question asks about the ambiguous cases of a triangle. This topic is no longer in the E.Maths syllabus and it appears only in the 70s and early 80s "O" level exam.

  By the way, the answer is

  (1)   For two triangles, BC  < 5 cm

  (2)   For one triangle, BC > 5 cm

  (3)   For zero triangle, BC < 3 cm

  Thank you for your kind attention.

  Regards,

  ahm97sic

   

  Anyway, for clarification, it is in my E Maths Textbook and my maths teacher had spoke for this for 1 period

• Ahm97sic

  13 Oct 08, 11:01

  Hi SBS n SMRT,

  Can you share with us which textbook that you are using ?

  Thanks.

  Regards,

  ahm97sic

   

   

• flyPiggy

  14 Oct 08, 16:55

  Originally posted by SBS n SMRT:

  Anyway, for clarification, it is in my E Maths Textbook and my maths teacher had spoke for this for 1 period

  does this means that this will come out? i think i know how to do but just to be sure, can anyone post the correct method here?

• Ahm97sic

  14 Oct 08, 17:18

  Hi flyPiggy,

  You may refer to the MOE website for the new 2008 E. Maths (4016) detailed syllabus

  http://www.seab.gov.sg/SEAB/oLevel/syllabus/2008_GCE_O_Level_Syllabuses/4016_2008.pdf

  for the details.

  Thank you for your kind attention.

  Regards,

  ahm97sic

  PS : SBS n SMRT has claimed that the topic is in his E.Maths textbook (assumed to be the latest textbook written for the new 2008 E. Maths (4016) syllabus) and yet he is not sharing the name of the textbook with us. So ???

  If Mr Wee_ws, author of the "O" E.Maths year by year and topic by topic ten years series published by MOE authorised publisher Dyna sees this thread, perhaps he can kindly confirm whether this topic (ambiguous cases of a triangle) is still in the new 2008 E. Maths (4016) syllabus. Mr Wee is also a forumer on this homework forum and Eagle, the moderator has also sent him an invitation to be a moderator of this forum too.