Fill in the blanks: the circumference of a semicircle is 25.7cm, and its area is () square centimeter

Fill in the blanks: the circumference of a semicircle is 25.7cm, and its area is () square centimeter

Radius = 25.7 ÷ (3.14 + 2) = 5cm
Area = 5 × 5 × 3.14 × 1 / 2 = 39.25 square centimeter

The circumference of a semicircle is 25.7 cm. How many square centimeters is its area?

The radius of the semicircle is: 25.7 △ 3.14 + 2, = 25.7 △ 5.14, = 5 (CM); so the area of the semicircle is: 3.14 × 52 △ 2 = 39.25 (square cm); answer: its area is 39.25 square cm

1. The circumference of a circle is 25.12 cm, the circumference of a semicircle is (), and the area of a semicircle is ()
If the denominator is added with 4, it will be 1 / 4. The original fraction is ()

1. The circumference of a circle is 25.12 cm, the circumference of a semicircle is (20.56 cm), and the area of a semicircle is (25.12 square cm)
2. The numerator of a fraction plus 1 is 1 / 3. If the denominator plus 4 is 1 / 4, the original fraction is (7 / 24)