Answer:
81°
Step-by-step explanation:
the sum of angles in a triangle is 180°
Looking at the triangles, both look the same so each sides are equal therefore all sides are 60°
the sum of angles at the centre is 360°
60° + 60° + 78° + 2x° = 360°
198° + 2x° = 360°
2x° = 360 - 198 = 162°
x= 162/2 = 81°
