A quadrant of a circle of radius 6 cm is cut away from each corner of a rectangle 25 cm long and 18 cm wide. Find the perimeter of the remaining figure.
Worked solution (try it first)
Each corner cut takes 6 cm off both sides that meet there.
The straight edges left are 2(25−12)+2(18−12)=26+12=38 cm.
Each corner now has a quarter-circle arc of radius 6.