The area of a circle is half of that of a semicircle. The circumference of a circle is 18.84 cm. How many cm is the circumference of a semicircle The area of a circle is half of that of a semicircle. The circumference of a circle is 18.84 cm. What is the circumference of a semicircle?

The area of a circle is half of that of a semicircle. The circumference of a circle is 18.84 cm. How many cm is the circumference of a semicircle The area of a circle is half of that of a semicircle. The circumference of a circle is 18.84 cm. What is the circumference of a semicircle?

Given that the circumference of a circle is 18.84, we can find that 18.84 / 3.14 = 6 is the diameter of the circle, so the area of the circle is 3.14 * (6 / 2) &# = 28.26, because the circle is half of the semicircle, so the area of the semicircle is 28.26 * 2 = 56.52, then the radius of the semicircle is 56.52 * 2 / 3.14, the following square is equal to 6, and the perimeter is equal to 6 * 3.14 / 2 + 6

The sum of the diameters of the two circles is 30 cm. If the radius of one circle is r cm, what is the circumference of the other circle? What is the area?

If the sum of the diameters of the two circles is 30 cm, then the sum of the radii of the two circles is 15 cm
So the radius of the other circle is 15-rcm
So the perimeter of the other circle is 2 π (15-r)
The area is π (15-r) &# 178;