Column I

1. $x = \frac { - b \pm \sqrt { b ^ { 2 } - 4 a c } } { 2 a }$ 

2. $\frac { \operatorname { sin } A } { a } = \frac { \operatorname { sin } B } { b }$ 

3. $c^2=a^2+b^2$ 

4. $c^2=a^2+b^2−2ab\ \cos C$ 

Column II

1. Law of Cosines

2. Law of Sines

3. Pythagorean Theorem

4. Quadratic Formula