Let each side of a square is 20cm. Four equal circle each of radius 10cm, are drawn about the four corners of the square so that each touches two of the others. Find the area enclosed between the circumferences of the circles.

The four quarter-circles at the corners of the square together form a complete circle with radius 10 cm. The square has side 20 cm, so its area is 400 cm². The area of the full circle is π × 10² = 100π ≈ 314 cm². The area between the circumferences = area of square - area of circle = 400 - 100π ≈ 400 - 314.16 = 85.84 ≈ 86 cm².