Answer:
C
Step-by-step explanation:
sin x= CB/CA =4/8
......
This is number 8. the second person got number 9
Area of the trapezoid:

Area of the rectangle:
4.2 x 3.1 = 13.02 cm^2
Area of each quarter circle:

We have two quarter circles:
7.54 + 7.54 = 15.08
41.65 + 13.02 + 15.08 = 69.75 cm^2
The options you gave are extremely confusing, but if you round 7.9 it is 8, and if you round $3.89 it is $4. Therefore, the best estimate would be 8•$4, or $32