The third one is the answer for this question
Since we need your monthly bill we will call it the variable B for now, (Unless you have the bill, if so replace it with the variable)
Multiply 1.64 x B since the exchange rate is different than the US bill,
For example, say your bill is $100 in the U.S.
You do 1.64 x 100 = A monthly bill of $164 if you lived in Britain

Actually Welcome to the Concept of the Equilateral Triangles.
Since, we know that, all the sides of a triangle are equal, hence it is a Equilateral triangle.
Equilateral triangle has one all angles equal to 60°.
so, major angle P = 60°
hence, 2x=60°
===> x = 30°