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.