alright so the triangle theorem states that all of the angles of a triangle add up to 180. we already of 130 so we take away 130 from 180 to get 50. If you see the two little lines on the triangles sides opposite of the two angles that we are missing then you can tell by those lines that the angles opposite of them are equal to each other. So you divide 2 from 50 to get 25 which is the value of x. Hope you understand this (:
