We can see that two sides of that triangle area equal
so, their corresponding angle will also be equal
now, we know that
sum of all angles in any triangle is always 180
so, we can get equation as
[tex]x+100+x=180[/tex]
now, we can solve for x
[tex]2x+100=180[/tex]
[tex]2x=80[/tex]
[tex]x=40[/tex]
so, option-C..............Answer
