Smile 發問於 社會及文化語言 · 1 年前

Maths problem, i don't know how to do and write the reason, because i don't know how to prove EC is perpendicular to BF, thanks?

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1 個解答

  • 1 年前

    side BC = side FC and side BE = size EF, thus triangle BCE and FCE triangle are similar per SSS similarity theorem.

    So, the angle BEC and the angle FEC are the same, thus 90 degrees.

    So proved.