The right triangles
and
are similar and have opposite orientation. The right angles are at
and
, and we also have
. Let
be the point of intersection of the lines
and
. Prove that if the lines
and
exist, they are perpendicular.
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The right triangles $ABC$ and $AB_1C_1$ are similar and have opposite orientation. The right angles are at $C$ and $C_1$, and we also have $\angle CAB = \angle C_1AB_1$. Let $M$ be the point of intersection of the lines $BC_1$ and $B_1C$. Prove that if the lines $AM$ and $CC_1$ exist, they are perpendicular.