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,

Answer:
90
Step-by-step explanation:
100%-10%=90%
90%->81
10%->9
100%->9+81=90
Answer: 23
Step-by-step explanation: