See56.7 cause it is the correct one to the 20th
Answer:
The correct option is C ) 109.5°
Therefore,

Step-by-step explanation:
Given:
In Triangle DEF
d = 10
e = 18
f = 12
To Find
angle E = ?
Solution:
In Triangle DEF , Cosine Rule says

Substituting the values we get


Therefore,

............As it is in Second Quadrant
Therefore,

It would be: k+3 = 10
subtracting 3 from both sides,
k+3-3 = 10-3
k=7
Answer:
the answer is 14 C
Step-by-step explanation:
just took the test?