Answer:
[tex] X = 70.5 [/tex]
Step-by-step explanation:
The law of Cosine given can be written in another form to make the Cos(C) the subject of the formula. Which is: [tex] cos(C) = \frac{a^2 + b^2 - c^2}{2ab} [/tex]
Where,
a = 20 ft
b = 18 ft
c = 22 ft
C = X
[tex] cos(X) = \frac{20^2 + 18^2 - 22^2}{2*20*18} [/tex]
[tex] cos(X) = \frac{400 + 324 - 484}{720} [/tex]
[tex] cos(X) = \frac{240}{720} [/tex]
[tex] cos(X) = 0.3333 [/tex]
[tex] X = cos{-1}(0.3333) [/tex]
[tex] X = 70.5 [/tex]
