Let the vertex angle be A......then the exterior angle is (180-A)

It is given that the exterior angle is 3 times the measure of vertex angle i.e, A.....hence (180-A) = A

180 = 4A

A = 180/4 = 45

Hence the vertex angle is obtained as 45 degrees

Since in isoceles triangle the other two angles(say B) are equal....therefore A + B + B = 180

45 + 2B =180

2B = 135

B = 135/2 = 67.5

Hence the three angles of triangle are 45, 67.5 and 67.5 degrees.

Let the vertex angle be A......then the exterior angle is (180-A)

It is given that the exterior angle is 3 times the measure of vertex angle i.e, A.....hence (180-A) = A

180 = 4A

A = 180/4 = 45

Hence the vertex angle is obtained as 45 degrees

Since in isoceles triangle the other two angles(say B) are equal....therefore A + B + B = 180

45 + 2B =180

2B = 135

B = 135/2 = 67.5

Hence the three angles of triangle are 45, 67.5 and 67.5 degrees.