$x=180-90^{\circ}-40^{\circ}=50^{\circ}$;
$y=180^{\circ}-70^{\circ}-x=180^{\circ}-70^{\circ}-50^{\circ}=60^{\circ};$
Tam giác ADC có AD = AC, suy ra tam giác ADC cân tại A, suy ra $v=70^{\circ}$;
$t=180^{\circ}-70^{\circ}-v=180^{\circ}-70^{\circ}-70^{\circ}=40^{\circ}$;
$z=180^{\circ}-90^{\circ}-y=180^{\circ}-90^{\circ}-60^{\circ}=30^{\circ}$.