Respuesta :

cos 35 = 12cm / hypotenuse (H)
0.81 = 12 / H 
H = 12/0.81 = 14.8
h^2 = x^2 + 12^2
219.04 = x^2 + 144
x^2 = 75.04 
x = 8.6 (~8.4)
so it is (c)
tan 35°=X/12
0.700=X/12
X=12×0.700
X=8.4
therefore X = 8.4cm