The area of the shaded region is 78 square inches. All angles are right angles and all measurements are given in inches. What is the perimeter of the non-shaded region?
10*9 = 90 in2 =total area
so small rectangle area = 90 -78 = 12 in2
2 * x = 12 in2
x = length = 6 in
perimeter is thus 2+2 + 6+ 6 = 16 in
