mohon di jawab pertanyaannya!!!

TriGonoMetRi

a + b + c = 180°

sin a = 4/5
cos a = √(1 - sin² a) = 3/4

cos b = 5/13
sin b = √(1 - cos² b) = 12/13

c = 180° - (a + b)

sin c
= sin (180° - (a + b))
= sin (a + b)
= sin a cos b + cos a sin b
= 4/5 . 5/13 + 3/5 . 12/13
= (20 + 36)/65
= 56/65 ✔