8. One angle of an isosceles triangle is $30^{\circ}$. Which of the following could be the difference between the other two angles?
A $30^{\circ}$
B $60^{\circ}$
C $70^{\circ}$
D $80^{\circ}$
E $90^{\circ}$
8. E Since one angle of the isosceles triangle is $30^{\circ}$, there are two possibilities. Either the other two angles are equal, in which case the difference between them is $0^{\circ}$, or one of the other angles is $30^{\circ}$. In this case, since angles in a triangle add to $180^{\circ}$, the second missing angle is $120^{\circ}$ and hence the difference between the two missing angles is
$$
120^{\circ}-30^{\circ}=90^{\circ} \text {. }
$$