Because it's iscosceles, angle 1 is similar size to the angle on the right leg. ∠1 = 67°
The sum of interior angles in trapezoid equals to 360°. And because it's iscosceles, the upper angles are in the same size. We can write it as, the sum of angles = 360° 67° + 67° + ∠2 + ∠2 = 360° 134° + 2 × ∠2 = 360° 2 × ∠2 = 360° - 134° 2 × ∠2 = 226° ∠2 = 113°
