1. ## The sign rule?

In the triangle ABC, a= 10, b= 12 and B= 58°. Find A, C and c.

Here is what I've done so far:

b/sin B = a/sin A
12/sin 58° = 10/sin A
sin 58°/12 = sin A/10
sin A = (10 * sin 58°)/12
A = inverse sin (10 * sin 58°/12)
= 44 degrees and 58 minutes

What do I do next? How can I find C and c? If anyone could show me the complete working out to the rest of the problem that would be appreciated! And please keep the working out simple...I'm new at this!

2. Originally Posted by Joker37
In the triangle ABC, a= 10, b= 12 and B= 58°. Find A, C and c.

Here is what I've done so far:

b/sin B = a/sin A
12/sin 58° = 10/sin A
sin 58°/12 = sin A/10
sin A = (10 * sin 58°)/12
A = inverse sin (10 * sin 58°/12)
= 44 degrees and 58 minutes

What do I do next? How can I find C and c? If anyone could show me the complete working out to the rest of the problem that would be appreciated! And please keep the working out simple...I'm new at this!
$
A + B + C = 180^{\circ}
$

3. Blast! How obvious was that?