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# help!

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In triangle PQR, PQ = 13, QR = 14, and PR = 15. Let M be the midpoint of QR. Find PM.

Jun 19, 2020

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From Herons formula we have the area as

$$[PQR] = \sqrt{(21)(21-13)(21-14)(21-15)} = \sqrt{(21)(8)(7)(6)} = 7\cdot 3\cdot 4 = 84.$$

$$[PQR] = \frac12(QR)(PH) = 7PH$$

Does this help?

Jun 19, 2020