## Thinking Mathematically (6th Edition)

$A \approx 23^o$
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 tangent formula to obtain: $\tan{A} = \dfrac{\text{length of opposite side}}{\text{length of adjacent side}} \\\tan{A}=\dfrac{10}{24} \\\tan{A} = 0.41\overline{6}$ Use the inverse tangent function of a scientific calculator to obtain: $A = \tan^{-1}{0.6} \\A = 22.61986495^o \\A \approx 23^o$