Chapter 5 - Trigonometric Functions - 5.3 Trigonometric Functions Values and Angle Measures - 5.3 Exercises - Page 531: 12

$\sin A=\frac{45}{53}$ $\cos A=\frac{28}{53}$ $\tan A=\frac{45}{28}$

$\sin A=\frac{\text{side opposite}}{\text{hypotenuse}}=\frac{45}{53}$ $\cos A=\frac{\text{side adjacent}}{\text{hypotenuse}}=\frac{28}{53}$ $\tan A=\frac{\text{side opposite}}{\text{side adjacent}}=\frac{45}{28}$