To find the unknown side length in a triangle, we need more information about the triangle's geometry. The values "20" and "30" represent lengths of sides, but we do not know the relationship between these sides (for instance, whether they are adjacent, opposite, or whether the triangle is right-angled).
If this is a right triangle with these sides given, we can use the Pythagorean theorem \( a^2 + b^2 = c^2 \), where \( c \) is the hypotenuse.
If we assume that the side of length 30 is the hypotenuse and 20 is one of the other sides, the other side would be calculated as follows:
- \( a = 20 \) (one side)
- \( b = x \) (unknown side)
- \( c = 30 \) (hypotenuse)
Applying the Pythagorean theorem:
\[ 20^2 + x^2 = 30^2 \] \[ 400 + x^2 = 900 \] \[ x^2 = 900 - 400 \] \[ x^2 = 500 \] \[ x = \sqrt{500} \] \[ x \approx 22.36 \]
Therefore, if the triangle was right with 30 as the hypotenuse, the unknown side length would be approximately \( 22.36 \) (rounded to nearest hundredth).
Please check the problem’s context and clarify if this is indeed a right triangle or provide additional information about the triangle.