## Thinking Mathematically (6th Edition)

$A \approx 37^o$
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: $\sin{A} = \dfrac{\text{length of opposite side}}{\text{length of hypotenuse}} \\\sin{A}=\dfrac{30}{50} \\\sin{A} = 0.6$ Use the inverse function to obtain: $A = \sin^{-1}{0.6} \\A = 36.86989765^o \\A \approx 37^o$