Answer:
50degrees
Explanation:
The sum of angle in the triangle XYZ is 180degrees, hence;
<X + <Y + <Z = 180
Given
m<X = 80degree
m<Y = m<Z
Required
m<Z
Substitute the given angle
80 + m<Z + m<Z = 180
80 + 2m<Z = 180
2m<Z = 180 - 80
2m<Z = 100
m<Z = 100/2
m<Z = 50degrees
Hence the measure of angle Z is 50degrees