Answer:
X = 40°
Y = 78°
Step-by-step explanation:
Since the two angles at the bottom are parallel as it is shown that the triangle is an isosceles triangle (which means 2 angles in a triangle are the same while the one other is different)
51 - 11 = 40 (X)
Since we found out 2 angles in the triangle...
51 + 51 = 102
180 - 102 = 78 (Y)
