C=2 pie r
(example circumference=28)
28=2 x 22\7 x r
28=6.29r
then divide both sides by 6.29
28\6.29=4.45
r=4.45
15.04 degrees or answer A is correct.
The Law of Sines is the relationship between the sides and angles of non-right (oblique) triangles . Simply, it states that the ratio of the length of a side of a triangle to the sine of the angle opposite that side is the same for all sides and angles in a given triangle. The formula for it is A=b•sin a/sin b.
You can transform the law of sines formulas to solve some problems of triangulation (solving a triangle). You can use them to find:
The remaining sides of a triangle, knowing two angles and one side.
The third side of a triangle, knowing two sides and one of the non-enclosed angles. In some cases (ambiguous cases) there may be two solutions to the same triangle. If the following conditions are fulfilled, your triangle may be an ambiguous case:
You only know the angle α and sides a and c;
Angle α is acute (α < 90°);
a is shorter than c (a < c);
a is longer than the altitude h from angle β, where h = c * sin(α) (a > c * sin(α)).
I hate useless complicated math lol ;)
