14) CHALLENGE: Find the values of the missing variables.

99 points at a zoo, the leopard pen has a ring-shaped sidewalk around it. the outer edge of the sidewalk is a circle with a radius of 12 m. the inner edge of the sidewalk is a circle with a radius of 8 m. (1 point for showing all of your work) a. write and simplify an expression for the exact area of the sidewalk. (1 point for the answer) b. find the approximate area of the sidewalk. use 3.14 to approximate π. (1 point for the answer)

Factor completely. 4p^2 + 36p + 81 express the answer in the form (ap + b)^2

Ntriangle abc, m∠a = 35° and m∠b = 40°, and a=9. which equation should you solve to find b?