Question

  O valor de a no triangulo ABC é: a) 32 b) 36 c) 30 d) 34


     C
      |    \
      |      \
 18 |        \a
      |          \
      |____38º\
    A                B                         me ajuda!!

Answer 1

Se for 30º)                              sen(30)=18/a

                                              1/2=18/a

                                               a=36

Se for 38º)                             sen(38)=18/a

                                               0,616=18/a

                                                a=18/0,616

                                                a=29,22079...

                                               

Answer 2

Temos:
seno = cateto oposto/hipotenusa
38º=18/a
0,61=18/a
0,61a=18 => a=18/0,61 =~30
Letra C