Question

Determine o valor da medida de x, nos triângulos abaixo:

Answer 1

$\large\boxed{\begin{array}{l}\tt a)~\sf x^2=3^2+1^2-2\cdot3\cdot1\cdot cos(60^\circ)\\\sf x^2=9+1-\backslash\!\!\!2\cdot3\cdot1\cdot\dfrac{1}{\backslash\!\!\!2}\\\sf x^2=10-3\\\sf x^2=7\\\sf x=\sqrt{7}\end{array}}$

$\large\boxed{\begin{array}{l}\tt b)~\sf x^2=5^2+8^2-2\cdot5\cdot8\cdot cos(60^\circ)\\\sf x^2=25+64-\backslash\!\!\!2\cdot40\cdot\dfrac{1}{\backslash\!\!\!2}\\\sf x^2=89-40\\\sf x^2=49\\\sf x=\sqrt{49}\\\sf x=7~cm\end{array}}$