What you're seeing here is 12 being multiplied by its reciprocal. 12 * 1/12 = 1. This is an example of a multiplicative inverse; a multiplicative inverse is when you multiply a number by its reciprocal (1 over the number).
The correct answer is:
A=4
B=5
hopes this helps you and future people!
Answer:
The amount of water left is 1550 litres
Either or can be used with any triangle...I personally find the law of sines is often more compact as in this case we can just say;
(sin115)/18=(sin40)/c (with no need for b or B as would be needed with the law of cosines...)
c=18(sin40)/(sin115)
c≈12.77
