SOLUTION: Given: an isosceles triangle def with de=fe and exterior angle efg
prove m < efg is greater than m < efd
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-> SOLUTION: Given: an isosceles triangle def with de=fe and exterior angle efg
prove m < efg is greater than m < efd
Log On
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
Egw to Beta kai to Sigma
My calculator said it, I believe it, that settles it
