Well all the angles in a triangle add up too 180º and this triangle is obviously a equilateral triangle (all sides are same) BUT as you see the other people saying X = 60º notice that it says 2 xº meaning that it is X x 2 so 60º is actually wrong :).
If it is X is 60º (since the 3 angles add together since it’s equilateral) then that would be 2 x 60º = 120º times 3 WHICH IS NOT 180.I think U get what I mean now,it’s 2 Xº; so X is 30 because 30 x 2 = 60º and 60 x 3 = 180º!
So Da Answer is X = 30º
Hope this helped :)
Have a great day!