Desargue\( \prime \)s Theorem

The triangles \( A_1B_1C_1 \) and \( A_2B_2C_2 \) are perspective with respect to a center if the lines \( A_1A_2 \), \( B_1B_2 \), and \( C_1C_2 \) are concurrent. They are perspective with respect to an axis if the points \( K=B_1C_1\cap B_2C_2 \), \( L=A_1C_1\cap A_2C_2 \), \( M=A_1B_1\cap A_2B_2 \) are colinear.

Theorem 3 (Desargue\( \prime \)s theorem)
 
Two triangles are perspective with respect to a center if and only if they are perspective with respect to a point.


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