In the figure, `angle CBE` is an exterior angle which is equal to the opposite interior angle at the opposite vertex, `angle ADC`.
`therefore angle CBE=angle ADC` (1)
`angle CBE +angle EBY=180^@(because"linear pair")`
`therefore angle CBE =180^@-70^@=110^@`
`x^@=angle ADC=angle CBE =110^@`.
