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In triangle $PQR,$ $M$ is the midpoint of $\overline{QR}.$  Find $PM.$

 

 Dec 22, 2023
 #1
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[PR^2 - QR^2 - PQ^2 ] / [- 2 (QR * PQ] = cos PQR

 

[23^2 -25^2 - 18^2 ] / [ -2 (25 * 18) ] = cos PQR  = 7/15

 

PM^2  =   QM^2 + QP^2  - 2 (QM * QP) * cos PQR

 

PM^2 = 12.5^2 + 18^2 - 2(12.5 * 18)* (7/15)

 

PM = sqrt (270.25) ≈  16.44

 

 

cool cool cool

 Dec 23, 2023

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