Question

PLS HELP ME ASAP FOR 7, 8, 9. A and B!! (MUST SHOW WORK!!) + LOTS OF POINTS!!

Answer 1

7. 3.14(12^2 - 10^2)=3.14(144-100) = 3.14(44)=138.16
8. A = piR^2 = 50.24.   R^2 = 50.24/3.14 = 16.   R = 4cm
9a) Perimeter of square is 4*18 = 72.  Perimeter of circle is 2*pi*r.  r=9in
perimeter of circle is then 2*3.14.9 = 56.52.  Difference is 72-56.52 = 15.48
9b) Area of square is 18^2 = 324.
Area of circle is 3.14(9^2) = 254.34.  Difference is the unshaded part
324-254.34 = 69.66in^2