Question

find e and pls explain how

Answer 1

In an isosceles triangle
The angles next to the equal sides are equal
Here we can use linear pair to get an angle say x that’s right next to angle 123

123+x=180
x=57

therefore e will also be 57 due to the reason stated above.
Feel free to ask your teacher if you’re confused, they’ll help you out.
Happy learning.

Answer 2

123°+x = 180°
x = 180°-123°
x = 57
Therefore, e = 57