Question

09. Na figura ao lado, o valor de x é​

Answer 1

Explicação passo-a-passo:

Ângulo excêntrico exterior

$\sf \theta=\dfrac{\alpha-\beta}{2}$

$\sf 30^{\circ}=\dfrac{3x+12^{\circ}-x}{2}$

$\sf 30^{\circ}=\dfrac{2x+12^{\circ}}{2}$

$\sf 2x+12^{\circ}=2\cdot30^{\circ}$

$\sf 2x+12^{\circ}=60^{\circ}$

$\sf 2x=60^{\circ}-12^{\circ}$

$\sf 2x=48^{\circ}$

$\sf x=\dfrac{48^{\circ}}{2}$

$\sf \red{x=24^{\circ}}$