Question 688985
<font face="Times New Roman" size="+2">


Since de and fe are the equal sides of the isosceles triangle, angles d and f must be equal in measure.  Since the sum of the interior angles of any triangle is 180 degrees, there can only be one angle greater than or equal to 90 degrees in any triangle.  Since the measures of angles d and f are equal, they must therefore each measure less than 90 degrees.  By definition, the exterior angle at vertex f (efg) forms a straight angle with interior angle efd.  Hence the sum of efg and efd is 180 degrees. Since efd measures less than 90, efg must measure more than 90.  Q.E.D.


John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
<font face="Math1" size="+2">Egw to Beta kai to Sigma</font>
My calculator said it, I believe it, that settles it
<div style="text-align:center"><a href="http://outcampaign.org/" target="_blank"><img src="http://cdn.cloudfiles.mosso.com/c116811/scarlet_A.png" border="0" alt="The Out Campaign: Scarlet Letter of Atheism" width="143" height="122" /></a></div>
</font>