Answer
$Amplitude$ $=$ $3$
$Period$ $=$ $4\pi$
Work Step by Step
The highest point (amplitude) in the graph is at $y = 3$
$Divide$ $the$ $natural$ $period$ $of$ $a$ $sine$ $wave$ $2π$ $to$ $the$ $coefficient$ $of$ $x$ $inside$ $the$ $trigonometric$ $function$:
$Period$ $(T)$ $=$ $\frac{2\pi}{\frac{1}{2}}$ $=$ $2\times2\pi$ $=$ $4\pi$