Finding the value of x
The diagram shows an isosceles triangle with its vertices lying on two parallel lines.
Two straight lines are parallel.
Points A and B lie on the top parallel line.
Point C lies on the bottom parallel line.
Triangle ABC is isosceles with AC = BC.
The angle between AC and the lower parallel line at point C is 120°.
The angle between AB and the upper parallel line at point A is x°.
Find the value of x.