Question

Find x round to the nearest tenth

Answer 1

`X = 70.5`

Explanation:

The law of Cosine given can be written in another form to make the Cos(C) the subject of the formula. Which is:
`cos(C) = (a^2 + b^2 - c^2)/(2ab)`

Where,

a = 20 ft

b = 18 ft

c = 22 ft

C = X

`cos(X) = (20^2 + 18^2 - 22^2)/(2*20*18)`

`cos(X) = (400 + 324 - 484)/(720)`

`cos(X) = (240)/(720)`

`cos(X) = 0.3333`

`X = cos{-1}(0.3333)`

`X = 70.5`