1. Not finding help here? Sign up for a free 30min 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!

Vertices of Triangle

  1. Oct 27, 2009 #1
    A=(1,-1,-6), B=(4,4,2) and C=(-2,2,-4) are the vertices of a triangle.

    a) ||AB||^2 + ||BC||^2 = ||AC||^2
    b) ||AB||^2 + ||BC||^2 - ||CA||^2 = 152
    c) ||AB||^2 + ||BC||^2 + ||CA||^2 = 196
    d) The triangle has a right angle at A
    e) The triangle is a right triangle


    a) T
    b) F, should be sqrt152
    c) F, should be sqrt196
    d) Not sure
    e) Not sure

    Can somebody help me out here, please? I'll be very appreciated
     
  2. jcsd
  3. Oct 27, 2009 #2

    Mark44

    Staff: Mentor

    For a, b, and c, all your answers are wrong. What are you getting for |AB|^2, |BC|^2, and |AC|^2?

    For d, if you know the lengths of each side of a triangle, how can you tell if a particular angle is a right angle?
    For e, if you know the lengths of each side of a triangle, how can you tell whether any angle is a right angle?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook