if a line is drawn across the shape connecting two of the angles it makes two triangles. The sum of the angles in a triangle is 180 degrees. Since this shape makes two triangles the sum of the inside angles is 2 * 180 = 360 degrees
(2x - 17) + 90 + x + 59 = 360 combine like terms 3x + 132 = 360 3x = 360 - 132 3x = 228 x = 76
