SOLUTION
Consider the triangle shown below
This question will be solved using Pythagorean Theorem
Considering traingle KLN it follows:

Considering triangle LMN it follows:

Equate the x² values

Considering triangle KLM

Substitute the value of z² into the previous equation

Simplify the equation

Substitute y² into x²=y²+20²
![\begin{gathered} x^2=120+20^2 \\ x^2=120+400 \\ x^2=520 \\ x=\sqrt[]{520}^{} \\ x=2\sqrt[]{130} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/geo3e27kx9jep7gkprmtzl69poya9lj48i.png)
Therefore the value of LN is
![2\sqrt[]{130}](https://img.qammunity.org/2023/formulas/mathematics/high-school/teyc1yzw88s2dvw2kpgi71rwvtxcnqa16w.png)