Thread: using sine and cosine

A scalene Triangle With a Side A 12m Long Side B 5m long and one angle which is opposite length A at 2.1 rad

help with knowing the rest of the angles in degrees and also the other side please

Use the sine rule to find angle B.

Use the fact that the angles add to 180 degrees to find angle C.

Use the sine rule to find side c.

Or you could use the cosine law: with a= 12, b= 5, and A= 2.1 to get a quadratic equation to solve for c. Note that there may be two different values for c and so two different triangles.