Question

determine an expression to find the area of the shaded region for the figure. view picture: http://minus.com/mbfgK1cl58/

Please help

Answer 1

Find the area of the quadrilateral/square - the area of the circle. Does that help?
Area of circle = \[\pi r^2 \]Area of square = \[l \times w\]

Answer 2

i got 2r^2 - Pir^2 but the book says 4r^2 - Pir^2