The value of x is 5.41.
To find the measure of X in the given scenario, where X is the length of a side in a right-angled triangle and the angle opposite to it is
, the cosine function is utilized.
The cosine of an angle in a right-angled triangle is defined as the ratio of the adjacent side to the hypotenuse. In this case, the adjacent side is x and the hypotenuse is
. The cosine of an angle
is given by the formula:
![\[ \cos(\theta) = \frac{\text{Adjacent}}{\text{Hypotenuse}} \]](https://img.qammunity.org/2024/formulas/mathematics/college/mdsvokmeabcasa7w3z1yfxv5en8bbwdram.png)
For this problem:
![\[ \cos(26^\circ) = (x)/(78^\circ) \]](https://img.qammunity.org/2024/formulas/mathematics/college/sw4lww3rb2tx5nxxl15fzh0nsw2vaypsly.png)
To solve for x, rearrange the equation:
![\[ x = 78^\circ \cdot \cos(26^\circ) \]](https://img.qammunity.org/2024/formulas/mathematics/college/xc9988xf78hwnjn8a6elh3ypdbqz7mtk5h.png)
Using a calculator, evaluate
, and then multiply it by
to find x. Rounding to the nearest hundredth, the answer is approximately x = 5.41 .