According to the Triangle Angle Sum Theorem, the sum of the angles in a triangle is 180 degrees.
Given the angles are \( 2x \), \( 3x \), and \( 4x \), we can set up the following equation:
\[ 2x + 3x + 4x = 180 \]
Combining like terms:
\[ 9x = 180 \]
Now, solve for \( x \):
\[ x = \frac{180}{9} = 20 \]
Now we can find the measure of each angle:
- The first angle is \( 2x = 2(20) = 40^\circ \)
- The second angle is \( 3x = 3(20) = 60^\circ \)
- The third angle is \( 4x = 4(20) = 80^\circ \)
Among \( 40^\circ \), \( 60^\circ \), and \( 80^\circ \), the smallest angle is:
\[ \boxed{40^\circ} \]