Answer:
47.7° or 132.3°
Step-by-step explanation:
In A ABC, m B = 25°, b = 12 and c = 21. Find all possible mC to the
nearest degree.
We solve the above question using Laws of sines.
The formula is given as
b/sin B = c/sin C
b = 12
B = 25°
c = 21
C = ?
Hence:
12/sin 25 = 21/sin C
Cross Mulitiply
= 12 × sin C = sin 25 × 21
sin C = sin 25 × 21/12
C = arc sin (sin 25 × 21/12)
C = 47.7°
The second possible value of C =
180° - 47.7°
= 132.3°
Therefore, all the possible values of mC = 47.7° or 132.3°
