1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Trignometry Proof Help

  1. Apr 8, 2010 #1
    Trignometry Proof Help!!!

    If a,b,c are sides in a triangle such that a<1/2(b+c) show that angle A (the angle opposite to side a) is less than 60 degrees
     
    Last edited: Apr 8, 2010
  2. jcsd
  3. Apr 8, 2010 #2

    mathman

    User Avatar
    Science Advisor

    Re: Trignometry Proof Help!!!

    Have you tried the law of cosines?

    a2=b2+c2-2bccosA
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook