In a square with a side length of 20 cm, make four semicircles with each side as the diameter to the inside of the square. What is the area of the four lobes of the overlapping part?

In a square with a side length of 20 cm, make four semicircles with each side as the diameter to the inside of the square. What is the area of the four lobes of the overlapping part?

It's the total area of the four semicircles minus the area of the square

If the side length of a square is reduced by 2 cm, then the area is reduced by 28 square cm. How much is the area of the original square?

28 △ 2 = 14 (CM) 14 × 14 = 196 (cm 2)

With a 16 cm long wire folded into a 5 cm rectangle, its width is () cm, if folded into a square, the area is ()

3cm wide
The square area is 16 cm square