What is the length of MN

Answer:
Option A. [tex]MN=15\ units[/tex]
Step-by-step explanation:
we know that
An isosceles triangle has two equal sides and two interior equal angles
The triangle LMN is an isosceles triangle
therefore
[tex]ML=MN[/tex]
substitute the values
[tex]3x=x+10[/tex]
solve for x
[tex]3x-x=10[/tex]
[tex]2x=10[/tex]
[tex]x=10/2=5\ units[/tex]
Find the length of MN
[tex]MN=x+10[/tex] -----> [tex]MN=5+10=15\ units[/tex]