Question 237403
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statement:  &#8736;BAD &#8773; &#8736;CAD
reason: given
statement:    AD &#8773; AD
reason: a line segment is congruent to itself
statement: m&#8736;ADB = 90°
reason: given AD is perpendicular to BC
statement: m&#8736;ADC = 90°
reason: given AD is perpendicular to BC
statement:  &#8736;ADB &#8773; &#8736;ADC
reason: both angles have measure 90°, i.e., they are right angles.
statement:  &#8710;ABD &#8773; &#8710;ACD
reason: ASA of congruency of triangles
statement:    AB &#8773; AC
reason: CSCT. or corresponding sides of congruent triangles.
statement:  &#8710;ABC is isosceles
reason: &#8710;ABC has two sides congruent. 

Edwin</pre>