AE is parallel to BC because alternate internal angles are equal
How to find the alternate internal angles
From the given description, the given triangle is an isosceles triangle
Solving for base angles of isosceles triangle, x
x + x + 30 = 180
2x = 180 - 30
2x = 150
x = 75
ABC = ACB = x = 75 degrees
And ACB = EAC = 75° (alternate internal; angles are equal)