4. Determine the angle in isosceles triangle

In the following isosceles triangle \(ABC\), the exterior angle \(∠A = 80°\) and \(BC\) is the unequal side. Calculate interior angles \(∠B\) and \(∠C\).

 

 

1. \(∠B =\) \(°\).

2. \(∠C =\) \(°\).