Thinking Mathematically (6th Edition)

Thus, $a \approx 14$ m.
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.