In triangle ABC, altitudes are drawn from the vertices B and C on AC and AB respectively such that BL=CM. Prove that triangle BCM congruent triangle CBL.

In triangle ABC, altitudes are drawn from the vertices B and C on AC and AB respectively such that BL=CM. Prove that Triangle BCM congruent triangle CBL.

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 In the video, it must be givenon 1 of the sides  as triangle  DEF corresponds to triangle LNM .pls correct it.