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!

Homework Help: Trigonometry - Finding degrees of triangle

  1. May 24, 2007 #1
    I'm having problem with this question:

    From a point A, three straight lines are drawn to points R, S, T so that TRIANGLE ART is right-angled and points R , S, T are collinear. If AR = 12, AS=13, AT=37, determine the area of TRIANGLE AST.

    Is it ok to assume RAS and SAT is 45 degrees?
  2. jcsd
  3. May 24, 2007 #2
    no. your given 2 sides of triangle ARS find the 3rd side. then notice triangle ART. notice what you're given and determine your goal. :smile:
  4. May 24, 2007 #3


    User Avatar
    Homework Helper

    No, of course, you cannot assume things in mathematics. Everything has to be proven.
    Ok AR = 12, AS = 13, and AT = 37, so AR is the smallest of the three.
    So if ART is a right triangle, what should be the right angle, then, is it andle A, R, or T?
    Knowing the right angle, one can use the Pythagorean theorem, ie: a2 + b2 = c2, where c is the length of the hypotenuse in a right triangle.
    You should note that, the area of an triangle ABC can be calculated by:
    A = (1 / 2) AH x BC, there AH is its altitude.
    Can you go from here? :)
  5. May 24, 2007 #4
    Thank you guys so much :)
    That was very helpful
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook