## Trigonometry 7th Edition

$y\approx15.82$
$A=45^{\circ},s=18,r=15$ For arc-length, $s=r\cdot C$ $18=15\cdot C$ $C=\frac{18}{15} radian$ $C=68.76^{\circ}$ Using laws of sines, $\frac{r}{sinA}=\frac{y}{sinC}$ $\frac{15}{sin45^{\circ}}=\frac{y}{sin68.76^{\circ}}$ $y\approx15.82$