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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)
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What is the radius of the circle equal to?
Radius of a circle= Perimeter of the circle/2*pi Radius is half the diameter Radius is the length of a straight line from the center point of the circle to the edge of the circle.
What is the radius of a circle that is 7.1 cm?
If it is a 7.1 cm radius circle, then its radius is exactly 7.1 cm!
The circumference of a circle is 132cm what is the radius of the circle in centimeters?
If the circumference of a circle is 132cm its radius is: 21.01 cm
What is the diameter of a circle with a 9 radius?
The diameter of a circle is twice the radius. A circle with a radius of 9 would have a diameter of 18. (9*2=18).
How do you find the circumfrence of a circle if you have the radius?
the circumfrence of a circle is pi times it's radius squared.
What is the area of a circle with a radius of 20cm?
A = 1,257 cm2
What is the radius of a circle when the diameter is 20cm?
Radius = Diameter/2 = 10 cm
If a circle has a radius of 10 cm what is measure of circle's diameter?
WOW really? It would be 20cm
Where pi is 3.14 find the area of a circle with a radius of 20cm?
1256 cm2
What is the area of a circle with a diameter of 20 cm?
A circle with a radius of 10 cm has an area of 314.16 square cm
What is the radius if the dianeter is 40cm?
The Diameter is the distance from one side of the circle all the way to the other side. The Radius is half the distance in a circle. Simply put: 40cm = Diameter 20cm = Radius (Half the distance) :)
A wire of length 20cm is bent so as form arc of circle of radius 12cm what is the angle subtended at the center in radians is?
When the angle is measured in radians arc_length = angle x radius. So, 20cm = angle x 12cm => angle = 20cm / 12cm ~= 1.67 radians
What is the circumference of a circle if it has a radius of 6cm?
The formula for the circumference of a circle is C = 2πr, where C is circumference, π is pi (approx. 3.142), and r is the radius. So, for a circle with a radius of 6cm, C = 2(3.142)(6cm) = 18.852cm Rounding to the proper number of significant figures, this answer would be 20cm.
What is the surface are of a cylinder whose radius is 10cm and height is 20cm?
The surface are of a cylinder whose radius is 10cm and height is 20cm is 1884.96cm2
What is the area of a circle with a radius of 20cm and a diameter of 50cm?
This cannot be properly answered because a 20 cm radius equates to a 40 cm diameter. Also, a 50 cm diameter means a 25 cm radius.
What is the perimeter of a rectangle that is 20cm by 2cm which has a quarter circle of radius 11cm on one 20cm side running off the 2cm side using 3.14 for π?
Normally, the amount of the side of the rectangle below the quarter circle on it would expected to be calculated. However, the radius of the circle equals the amount that is subtracted, but in calculating the perimeter it has to be added back in again as it forms part of the perimeter. Thus the perimeter is the perimeter of the rectangle plus a quarter of the circumference of the circle. → perimeter = 2 × (20cm + 2 cm) + ¼ × 2 × π × 11 cm ≈ 44 cm + 3.14 × 11/2 = 61.27 cm.
An equilateral triangle surrounds a circle of radius 10 cm and is itself surrounded by a larger circle Find the radius of the bigger circle?
Make a sketch of the situation. From a corner of the equilateral triangle draw a radius of the large circle, and from an adjacent side draw a radius of the smaller circle. You should have formed a small right-angled triangle with a known side of 10cm. and known angles of 30o, 60o and 90o. (The interior angles of an equilateral triangle are each 60o.) The hypotenuse is the unknown radius of the larger circle. But since cos 60 = 0.5, it is evident that the hypotenuse is 20cm. long.
