Question 252012
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*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \angle BAD\ \ \] congruent to *[tex \LARGE \angle CAD\ \ \ ]Given


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ AD\ =\ AD\ \ \ ]Reflexive Equality


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ AD\ \perp\ BC\ \ \ ] Given


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \angle CDA\ \ \ ] is a right angle:  Definition of perpendicular.


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \angle BDA\ \ \ ] is a right angle:  Definition of perpendicular.


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \angle CDA\ =\ \angle BDA\ \ \ ] Both are right angles.


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \triangle CDA\ \ \ ] congruent to *[tex \LARGE  \triangle BDA\ \ \ ]  ASA.


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ AC\ =\ AB\ \ \ ] CPCTC


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \triangle ABC\ \ \ ] is isosceles.  Definition of isosceles.  Q.E.D.


John
*[tex \LARGE e^{i\pi} + 1 = 0]
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