Answer:
B = 143.13 degrees
sin (B) = sin (143.13) = 3/5 = 0.6
Step-by-step explanation:
Obtuse angles are the ones greater than 90 degrees but smaller than 180 degrees.
They belong to the second quadrant
We first find B'
tan (2*B') = 24/7
2*B' = arctan (24/7)
B' = 0.5*arctan (24/7)
B' = 36.869
But since B is from the second quadrant, this means that
B = 180 - B' = 143.13 degrees
sin (B) = sin (143.13) = 3/5 = 0.6
