Answer:
The angle measures approximately 18.19°.
Explanation:
Since we want to find the angle and we are given the side adjacent to the angle and the hypotenuse, we can use the cosine ratio. Recall that:
![\displaystyle \cos \theta = \frac{\text{adjacent}}{\text{hypotenuse}}](https://img.qammunity.org/2022/formulas/mathematics/high-school/kdphbbr48zvjdu1z24zwtznmkofa7ae22d.png)
The adjacent side is 19 and the hypotenuse is 20. Substitute:
![\displaystyle \cos \theta = (19)/(20)](https://img.qammunity.org/2022/formulas/mathematics/high-school/7at80kgmope934rbn9mrblrjahx1w2qu7b.png)
We can take the inverse cosine of both sides:
![\displaystyle \theta = \cos^(-1)(19)/(20)](https://img.qammunity.org/2022/formulas/mathematics/high-school/3cunchecevgealvz5k2ukwfms949ze87ze.png)
Use a calculator (make sure you're in Degrees Mode!). Hence:
![\theta \approx 18.19^\circ](https://img.qammunity.org/2022/formulas/mathematics/high-school/b1pw21muqnz0u1v64khh58lwvnjomgbrwz.png)
The angle measures approximately 18.19°.