80 is the fixed amount because it is a cost before you get their services. So basically the Y intercept. It is if you pay for an 80$ membership fee and then you are charged per month.
A = hb/2
A = (15)(11) / 2
A = 165/2
A = 82.5 <===
If this is the dance position you are describing, then the arm and the leg of the dancer both make "right" angles (90º angles) to the floor.
I think its 14 because in order to get to 28 but 2 you count 14 times saying 2×14
