The radius of the circle is: 9.549 cm
The diameter of a circle is twice its radius. Thus the radius of a circle is half its diameter. → a circle with a diameter of 15 cm has a radius of 15/2 cm = 7.5 cm
If the diameter is 12 cm the radius is 6 cm.
The diameter of a circle is double the radius. So a circle with a radius of 7 cm has a diameter of 14 cm.
The circumference of a circle with an 8 cm radius is: 50.27 cm
Radius = 40/2pi cm
The circumference of a circle with a radius of 5cm is: 31.42 cm
The perimeter of a quarter circle is 2 radii plus a quarter of the circumference of the whole circle: → 2 × radius + ¼ × 2 × π × radius = 32.13 cm → radius × (2 + π/2) = 32.13 cm → radius = 32.13 ÷ (2 + π/2) cm ≈ 9.00 cm
That depends what you mean with "a 20 cm. circle". If 20 cm. is the radius, you already have the answer. If 20 cm. is the diameter, the radius is half the diameter. (10cm)
The radius measures from the center of the circle to the perimeter (outside), so if the radius is 8.5 cm that would make the diameter of the circle 17 cm. (8.5 cm X 2 = 17 cm)
The radius is 5.00 cm.
10 cm
20 cm
20 cm
The side of the square is equal to the diameter of the circle, in this case 2a so the perimeter is 8a cm.
10 cm Cutting out a quarter of the circle doesn't affect the radius, which is half of the diameter.
The perimeter is pi*r + 2r = 92.6 cm