Respuesta :

calculista
we know that
if sin A=cos B
then 
angle A and angle B are complementary angles
so
A+B=90 degrees
in this problem
(x+34)+(2x+20)=90-------> 3x+54=90----> 3x=90-54-----> x=36/3----> x=12°

the answer is
the value of x is 12 degrees