An isosceles triangle, the ratio of its vertex angle to its base angle is 1:4, and its base angle is ()?

An isosceles triangle, the ratio of its vertex angle to its base angle is 1:4, and its base angle is ()?

Degree of vertex angle: 180 ° / (1 + 4 + 4) = 20 °
Base angle degree: 20 ° X4 = 80 degrees