Answer
Thus, $a \approx 14$ m.
Work Step by Step
RECALL:
In a right triangle,
$\sin{A} = \dfrac{\text{length of opposite side}}{\text{length of hypotenuse}}
\\\cos{A} = \dfrac{\text{length of adjacent side}}{\text{length of hypotenuse}}
\\\tan{A} = \dfrac{\text{length of opposite side}}{\text{length of adjacent side}}$
Use the sine formula to obtain:
$\sin{A} = \dfrac{\text{length of opposite side}}{\text{length of hypotenuse}}
\\\sin{49^o}=\dfrac{a}{18}$
Multiply 18 to both sides of the equation to obtain:
$\sin{49^o} \cdot 18 = a
\\13.58477244= a
\\14 \approx a$
Thus, $a \approx 14$ m.
