Answer:
[tex]\theta=54.25\°[/tex]
Step-by-step explanation:
we know that
When the sine of angle X is equal to the cosine of angle Y, then angle X and angle Y are complementary angles
so
[tex]X+Y=90\°[/tex]----> equation A
In this problem
[tex]X=\theta[/tex]
[tex]Y=(\theta-18.5)[/tex]
substitute in the equation A
[tex]\theta\°+(\theta-18.5)\°=90\°[/tex]
[tex]2\theta=90+18.5[/tex]
[tex]2\theta=108.5[/tex]
[tex]\theta=54.25\°[/tex]