Question

Obtenha o valor de x da figura. Usar teorema dos cossenos.

Answer 1

$x^{2} = 4^{2} + (3 \sqrt{3} )^{2} -2.4.3 \sqrt{3} . cos 30^{o}$

$x^{2} = 16 + 27 -2.12 \sqrt{3} . \frac{ \sqrt{3} }{2}$

$x^{2} = 43 -12 \sqrt{3} . \sqrt{3}$

$x^{2} = 43 -12 .3$

$x^{2} = 43 -36$

$x^{2} = 7$

$x= \sqrt{7}$