Tolong dijawab beserta caranya yaa

Tolong dijawab beserta caranya yaa

Jawaban:

C

Penjelasan dengan langkah-langkah:

$cos( beta ) = frac{sa}{mi} \ cos(45) = frac{9}{x} \ x = frac{9}{ frac{ sqrt{2} }{2} } \ x = 9 times frac{2}{ sqrt{2} } \ x = frac{18}{ sqrt{2} } times frac{ sqrt{2} }{ sqrt{2} } \ x = frac{18 sqrt{2} }{2} \ x = 9 sqrt{2}$