ANSWER
The required angle is

EXPLANATION
Let the angle whose sine is

be

Then

We take the inverse sign of both sides to obtain,

We use our scientific calculator to evaluate and obtain,
Answer:
16
Step-by-step explanation:
10 + sqrt(y) = 14
Subtract 10 from each side
10 -10+ sqrt(y) = 14-10
sqrt(y) = 4
Square each side
(sqrt(y)) ^2 = 4^2
y = 16
Create formulas!
x=number of adult tickets
y=number of student tickets
x+y=644 <em>total sold</em>
56+y=x <em>student was 56 less than adult</em>
Perform substitution
(56+y)+y=644
56+2y=644
2y=588
y=294
Substitute y into the formula we created
x+294=644
x=350
350 adult tickets were sold.