There are two -main- approaches to answer this problem. By using the sine identity, or applying law of sines.
We'll do the sine trig. identity, as it is the most effective.
Given an angle '
![\alpha](https://img.qammunity.org/2019/formulas/mathematics/high-school/y6v92ecu39q3viwwe10drntgizvdkj4567.png)
' in a right triangle, '
![sin( \alpha )](https://img.qammunity.org/2019/formulas/mathematics/high-school/db9ggt99c46yw1j9d8fhd3ner8flkzvmta.png)
' is defined as the opposite side of the triangle to the given angle, over the triangle's hypotenuse.
So, for this setup:
![sin(20)= (x)/(10)](https://img.qammunity.org/2019/formulas/mathematics/high-school/60okdsm0ypclxwlrsbhokyazc5f5as1ddb.png)
Now, we solve for x:
So, answer is 3.4