Question

In ΔPQR, the measure of ∠R=90°, QP = 29, RQ = 21, and PR = 20. What ratio represents the cosine of ∠P?

Answer 1

Answer:

cos(P) = 20/29

Step-by-step explanation:

Given the following information:

• ∠R=90°,
• QP = 29
• RQ = 21
• PR = 20

To ratio represents the cosine of ∠P we use the cosine law (please have a look at the attached photo)  

$RQ^{2}$ =$QP^{2}$+ $PR^{2}$ − 2QP*PRcos(P)

<=> cos(P)  = ($QP^{2}$+ $PR^{2}$ - $RQ^{2}$) / 2QP*PR

<=> cos(P) =( $29^{2} + 20^{2} - 21^{2}$) /2*29*20

<=> cos(P) = 20/29

Hope it will find you well.