Answer
$y = 13.1$ units
Work Step by Step
1. Find $\angle C$
$\angle C = 180 - (60 + 40)$
$=180 - 100$
$= 80^{\circ}$
2. Use the sine law to find $y$
$\frac{y}{sin(40)} = \frac{20}{sin(80)}$
$y = \frac{20sin(40)}{sin(80)}$
by GDC / calculator
$y = 13.0540...$ units
$y = 13.1$ units
