2 isosceles triangles ABC and ABD have the same base AB but are in different planes.(adsbygoogle = window.adsbygoogle || []).push({});

Prove that CD is perpendicular to AB.

(It must be proved that CD is perpendicular to one of the planes and then it is perpendicular with every segment of this plane.)

Thanks in advance!

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# Homework Help: Geometry with isosceles triangles

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