Answer:
m∠A = 13.0°
Explanation:
- Because we don't know whether this is a right triangle, we will need to use the Law of Sines to find m∠A.
- The Law of Sines consists of three equations that relate the sines of a triangle's angles and its sides.
The three ratios are:
sin A / a = sin B / b = sin C / c
Thus, we can plug in 72 for B, 38 for b, and 9 for a to find m∠A:
(sin A / 9 = sin 72 / 38) * 9
sin^-1 ((sin 72 / 38) * 9) = A
13.01759287 = A
13.0 = A
Thus, A is about 13.0°.