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A quadrilateral ABCD is drawn to circumscribe a circle. Prove that `A B+C D=A D+B C` |
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Answer» Please refer to diagram in the video. As we know, tangents drawn from a point to a circle are always equal.So, `CR=CQ,PB=BQ,AP=AS and DR=DS` So,`CR+PB+AP+DR = CQ+BQ+AS+DS` `(CR+DR)+(PB+AP) = (CQ+BQ)+(AS+DS)` As, `CS+DR = CD` `PB+AP = AB` `CQ+BQ=BC` `AS+DS=AD` So,`AB+CD = AD+BC` |
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