Use 51.4cm wire to form a semicircle. What's the area of the semicircle? Besides, shouldn't the circumference of the semicircle be π D + D?

Use 51.4cm wire to form a semicircle. What's the area of the semicircle? Besides, shouldn't the circumference of the semicircle be π D + D?
Radius 51.4 △ 3.14 + 2 = 10 cm
Area: 3.14 × 10 × 10 × 1 / 2 = 157 square centimeter

It is known that the circumference of the semicircle is 51.4cm. What is the diameter of the semicircle? PS is all numbers. Thank you

Using the formula of semicircle circumference: 51.4 / (3.14 + 2) = 10 cm (radius)
10 * 2 = 20 cm (diameter)
A: the diameter of this semicircle is 20 cm

Find the circumference and area of the circle r = 1.5cm

Perimeter: 1.5 * 2 * 3.14 = 9.42
Area: 1.5 * 1.5 * 3.14 = 7.65

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