Answer:
1 = 31°
2 = 51°
3 = 51°
4 = 67°
Explanation:
1 is 31° because it alternates with the angle labelled 31°.
2 is 51° because it is in the same triangle as 1 and we know that the angle at the intersection of the diagonals are 90° and the sum of angles in a triangle is 180°.
3 is 51° because it alternates with the angle 2.