Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


bobmck
Posts:
15
From:
California
Registered:
6/29/09


Re: got different answer than one in book
Posted:
Mar 1, 2010 1:15 AM


On February 28, 2010, nancy wrote:
> The problem states: In Triangle ABC,m<B = 120, m<A = > 55, and D is the point on line AC such that line BC > bisects <ABC. Which is the longest side of triangle > ABD? I drew a diagram of a triangle I labeled ABC. > I drew a line from <B and labeled the end of it D. > C is obviously the largest angle,so the side opposite > it should be the longest side. I thought it should be > AD, but the book said it was AB. Why would that be? > > > Motherof8
************************************
Suspect a typo in the stated problem:
"such that line BC bisects <ABC" should read
"such that line BD bisects <ABC"
Triangle ABC, having 2 angles adding up to 175 means that <C must be 5, the smallest. Triangle ABD consists of <A = 55, half of <ABC (= 60) and <BDA. Again, since the interior angles of a triangle must add up to 180, that leaves <BDA = 65, the largest. So the side opposite it, AB, is longest. However, line AB is the shortest side of triangle ABC.



