Question

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

Answer 1

53/28

Explanation:

Answer 2

cos(P) = 20/29

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.