Question 600391
Let the congruent angles of the triangle are of measure X degrees
& the third angle is of measure Y degrees
So the angles of the triangle are X, X & Y

According to the question,the sum of the two congruent angles is thirty less than half the other angle
i.e.
X + X = {{{( Y/2 )-30}}}
2X = {{{( Y-60 )/2}}}
4X = Y - 60
OR Y = 4X + 60

as the sum of the angles of a triangle is 180 degrees, so
X + X + Y = 180
X + X + 4X + 60 = 180
6X + 60 = 180
6X = 180 - 60
X = 120/6
X = 20

so Y = 4(20) + 60 = 80 + 60 = 140


So the angles are 20, 20 & 140