Drawing: the intersection of a circle and a square is A, B, C and D, and the diagonal intersection of a square is O.
Using the knowledge of primary schools to solve problems is as follows:
The area of the square ABCD = ab× ad =/kloc-0 /×1=1m2.
The area of triangle AoB is 1/4 square area = 1/4m2.
The area of triangle AoB = OA× OB/2 = 1/4m2.
Therefore, oA×oB= 1/2.
The area of the circle o = OA× ob× ∏ =1/2× 3.14 =1.57m2.
(Note: ∏ take 3. 14)