help

Look at the hint: Law of Sines!

You need a calculator for this, but I'll help you through

angle B is 12 degrees and side b is 10 cm, so the ratio of sin B to b is \(\frac{\sin 12}{10}\).

This is 0.02079 (you need a calculator)

Can you now find side length a? angle A is 150 degrees, so do 0.02079=sin150/a and solve for a.

 

You are very welcome!

:P