Respuesta :

Answer:

58.9

Step-by-step explanation:

y²=x²+z²-2×z cos(y)

20²=22²+18²-2(22)(18) cos (y)

400=484+324-792 cos(y)

-408=-772 cos (y)

408/792=cos y

y=cos⁻¹(408/792)=58.9

hope it helps...

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