Chapter 7 - Applications of Trigonometric Functions - Section 7.2 The Law of Sines - 7.2 Assess Your Understanding - Page 551: 15

$A =40^\circ$ $a =2$ $c \approx3.06$

1. Find the third angle $A=180-100-40=40^\circ$ 2. Use the Law of Sines, we have $\frac{a}{sin40^\circ}=\frac{c}{sin100^\circ}=\frac{2}{sin40^\circ}$ 3. $a=\frac{2sin40^\circ}{sin40^\circ}=2$ 4. $c=\frac{2sin100^\circ}{sin40^\circ}\approx3.06$