Properties of isosceles triangle

Q.

Can a triangle have two acute angles why give reasons.

Q.

In $∆ABC,AB=AC$ and $\angle A=100°$, find $\angle B$ and $\angle C.$

Q.

If the equal angles of an isosceles triangle measures ${40}^{\circ }$each, then measure of the third angle is ____

1. ${50}^{\circ }$

2. ${60}^{\circ }$

3. ${70}^{\circ }$

4. ${100}^{\circ }$

Q.

Is the triangle with angles $\angle A=50°,\angle B=60°,\angle C=90°$ possible? Give reason for your answer.