A circle with diameter 6cm is cut from a square with side length 7cm. What is the remaining area of the square? You may assume pi = 3 for this question.

This is an example of a question that may appear in a calculator paper. In this question the area of the square and circle must be found individually, and the area of the circle subtracted from the area of the square. The area of a circle is equal to pir^2. Students may trip up by not distinguishing between the radius and diameter.
Solution:Area of square = 7cm7cm = 49cm^2Area of circle = 3*(6/2)^2 = 27cm^2Remaining area = 49-27=22cm^2