Answer:
A. 69°
Explanation:
Given:
m<FED = 179°
m<NED = 19x - 4
m<FEN = 12x - 3
Required:
m<FEN
Solution:
m<NED + m<FEN = m<FED (angle addition postulate)
19x - 4 + 12x - 3 = 179 (substitution)
Add like terms
31x - 7 = 179
31x - 7 + 7 = 179 + 7
31x = 186
31x/31 = 186/31
x = 6
✔️m<FEN = 12x - 3
Plug in the value of x
m<FEN = 12(6) - 3 = 72 - 3
m<FEN = 69°