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Problems
Mathematics
Mathematics
Problem
If the tangent at
A
A
A
to the circumcircle
A
B
C
ABC
A
B
C
meets
B
C
BC
B
C
at
X
X
X
then prove that
X
A
=
X
D
=
X
D
′
XA = XD = XD'
X
A
=
X
D
=
X
D
′
where
D
,
D
′
D, D'
D
,
D
′
are the points where the internal and external bisectors of
∠
A
\angle A
∠
A
meet
B
C
BC
B
C
respectively.
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