The wording of this question is a bit confusing... You can't write a sequence in sigma notation, but rather a series or sum. I think the question is asking you to write the sum of the sequence,

which would be

in sigma notation.
To do this, notice that the denominator in each term is a power of 2, starting with
and ending with
. So in sigma notation, this series is

All triangles equal 180 so the answer would be set up as follows:
180-60-90 (right triangle) = 30 degrees
30 degrees is the answer
Answer: Its B
Step-by-step explanation:
we know that
A difference of squares problem can be factored as follows:

in this problem we have

Applying difference of squares

the term

substitute

therefore
<u>the answer is</u>

I think x=9 hopefully I helped