Classifying TrianglesDate: 06/04/2002 at 20:50:30 From: George Springfiel Subject: triangles Tell whether the triangle is right, acute, or obtuse: 1. 4,5,6 2. 15,20,25 3. 5,7,10 Date: 06/04/2002 at 22:35:01 From: Doctor Ian Subject: Re: triangles Hi George, In a right triangle, the square of the longest side is equal to the sum of the squares of the other two sides. (This is the Pythagorean theorem.) Imagine a right triangle, |\ | \ c a^2 + b^2 = c^2 a | \ |___\ b Now imagine that we make the triangle acute, by keeping a and b the same length, but making c a little shorter. How could you detect that just by looking at the squares of a, b, and c? Now imagine that we make the right triangle obtuse, by making c a little longer, while keeping a and b the same length. How could you detect that just by looking at the squares of a, b, and c? Can you take it from here? - Doctor Ian, The Math Forum http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994- The Math Forum at NCTM. All rights reserved.
http://mathforum.org/dr.math/