
Trigonometry Trigonometry Math Forum 
 LinkBack  Thread Tools  Display Modes 
September 15th, 2016, 11:02 AM  #1 
Senior Member Joined: Jan 2015 From: London Posts: 108 Thanks: 2  Trigonometry and Circle Properties https://images1.discordapp.net/.eJw...bO7Gg4azXvZTZ4 I have done 3, a b and c but I can't do d. How do I get the angle of d? answers to a)87 b)53.1 c)90 
September 15th, 2016, 12:24 PM  #2 
Senior Member Joined: Jan 2015 From: London Posts: 108 Thanks: 2 
I missread c sorry i got that wrong ? can anyone help?

September 15th, 2016, 12:58 PM  #3 
Math Team Joined: Jul 2011 From: Texas Posts: 2,781 Thanks: 1432 
see attached thumbnail ...

September 15th, 2016, 01:01 PM  #4 
Senior Member Joined: Aug 2016 From: morocco Posts: 273 Thanks: 32 
d) angle ADB=180 angle BDO =180 angle OBD since OD=OB. Last edited by abdallahhammam; September 15th, 2016 at 01:08 PM. 
September 15th, 2016, 01:07 PM  #5 
Senior Member Joined: Jan 2015 From: London Posts: 108 Thanks: 2 
so for 4a and b are both 9.91 but for c how would you find out the angle A ? don't you need another angle in order to do that?

September 15th, 2016, 01:12 PM  #6 
Senior Member Joined: Aug 2016 From: morocco Posts: 273 Thanks: 32 
cos(OAB)=AB/OA=116/145.


Tags 
circle, properties, trigonometry 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Math questions (Derivative, unit circle, trigonometry etc)  Dani163  Elementary Math  14  June 2nd, 2016 04:16 PM 
properties of circle doubts  Alexis87  Algebra  3  August 4th, 2013 03:36 AM 
properties of circle doubts  Alexis87  Algebra  2  July 31st, 2013 01:34 PM 
Circle properties  Celluhhh  Algebra  1  May 1st, 2012 01:34 AM 
Graphing a circle TRIGONOMETRY  David_Lete  Algebra  5  April 11th, 2009 05:20 AM 