Answer:
x = 55°
y = 70°
z = 125°
Explanation:
Based on the Isosceles triangle theorem, since two sides of the triangle are congruent, therefore, the angles opposite to each of the equal sides are congruent.
Thus:
x = 180° - 125° (angles on a straight line/linear pair)
x = 55°
If x = 55°, the other base angle will also be 55°.
Therefore,
y = 180° - (55° + 55°) (sum of ∆)
y = 70°.
z = x + y (exterior angle of a ∆ theorem)
z = 55° + 70° (substitution)
z = 125°