145 divided by 7 =20.71
a little sketch on my answer <span />
B.
because {1,1,3,5,8}
{2,2,4,6,9}
you're just counting the numbers after the one that was given to you.
Theorem: If two chords intersect within a circle, then the product of the lengths of the segments (parts) of one chord is equal to the product of the lengths of the segments of the other chord.
In your case this theorem sounds as

Solve this equation:

Answer: correct choice is C.
Make an equation - example, two sides are 2x+60-4x+5=180
equal them to 180 because every triangle is equal to 180
when you find x, multiple two times x plus 60,
s x plus 5
thats the only thing i know about it