Question

A rectangle measures 18cm by 10cm

Four identical quarter-circles are removed to leave a shaded region
Work out the shaded area
Give answer in pi

Answer 1

lets work it out in terms of the radius r

area of the 4 identical quatrer circles = pi r^2

So the area of the shaded region is 18*10 - pi r^2
= 180 - pi r^2