diagram of triangle inside rhombus with illustrated angles
Triangle DFC is isosceles (CF=CD).

Hence DFC=FDC= x .

Hence FCD=(180-2x ) (angle sum of triangle).

Now EBC=FDC= x (opposite angles of a parallelogram) and triangle EBC is isosceles (CE = CB). Hence BEC= x and ECB=(180-2x )

Lines AD and BC are parallel and hence

ADC+BCD= 180 .

Therefore: x+2(180-2x)+60=180

i.e. 420-3x=180 i.e. 3x=240 i.e. x=80