Will give do i do 50 cosine 90 here? not sure.

x = 117.9°

Step-by-step explanation:

We require to find the size of the angle x

Given the law of cosines

c² = a² + b² - 2ab cosC

Rearrange to give cosC in terms of the sides

Add 2ab cosC to both sides

c² + 2ab cosC = a² + b² ( subtract c² from both sides )

2ab cosC = a² + b² - c² ( divide both sides by 2ab )

cosC =

here a = 55, b = 50 and c = 90 and C = x

cosx =

        =

        = ← - indicates angle is obtuse

x = ( ) ≈ 117.9°

move it to the other side

step-by-step explanation: