Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Triangle Rate Problem

  1. Nov 5, 2004 #1
    Hi, I'm having trouble with this one problem. I've been struggling to do it for hours! Ok maybe mins, but I still can't get the right answer. :frown:

    The altitude of a triangle is increasing at a rate of 3 centimeters/minute while the area of the triangle is increasing at a rate of 3.5 square centimeters/minute. At what rate is the base of the triangle changing when the altitude is 9.5 centimeters and the area is 99 square centimeters?

    The answer I got was 7/3.
  2. jcsd
  3. Nov 6, 2004 #2


    User Avatar
    Science Advisor

    A=area, b=base, h=altitude.

    b=2A/h. Therefore b'=2(hA'-Ah')/h2.

    You do the arithmetic. (I did not get 7/3).
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook