Given:
An isosceles triangle has two equal angles and one unequal angle
All angles of a triangle must add up to 180
One of the angles of the triangle is 122˚
Work:
Because an isosceles triangle has 2 equal sides, you know that the 122˚ angle can’t be the two equal angles because 122+122 is greater than 180 which would break the triangle.
Therefore, The 122˚ angle plus 2 identical angles that I will refer to as “a” have to add up to 180˚
122 + 2a = 180
a=29
So the only possible measure for the other two angles is 29˚