2. Area of a circle by using the diameter If we know the diameter of a circle, we can calculate the the area using, Area of a circle, \(A=\frac{{\pi}d^2}{4}\) This is because, \(r=\frac{d}{2}\), or the radius “r” is half of the diameter, “d”. ...
Circle Area Formulas To calculate the area of a circle, you’ll need its radius, diameter, or circumference. Then, use one of the following formulas. Find Area Using Radius The radius of a circle is the length of a straight line from the center of the circle to the outer edge. The mo...
The diameter of a circle is twice its ___. A. radius B. circumference C. area D. volume 相关知识点: 试题来源: 解析 A。“radius”是半径;“circumference”是周长;“area”是面积;“volume”是体积。圆的直径是半径的两倍。反馈 收藏
Area of a Circle Using Diameter | Formula & Examples from Chapter 1 / Lesson 8 148K Learn the formula for finding the area of a circle using the diameter with an applied example. Also, learn how to find the diameter and radius from the area. Related...
115.What is the ratio of the are a of Circle C to the are a of Square S if the lengths of a diameter of C and a side of S are equal?(; A.元:1 B.π:2 C.元:3 D.元:415. What is the ratio of theare a of Circle C to the are a of Square S if the lengths of a ...
To find the area of a circle, you take pi times the radius squared, or A = pi r^2. Using this formula, you can find the area of a circle if you know the radius — or the diameter — by plugging in your values and solving for A. Pi is approximated as 3.14. ...
You can use the diameter of a circle You can use the circumference of a circle How to find the area of a circle using the radius The radius of a circle is the distance from the center of the circle to a point on the circle. Once you know this distance, you simply need to substitut...
C. 36 D. 9π E. 18π 相关知识点: 试题来源: 解析 B The formula for the area of a circle is πr2. Therefore, the radius of this circle is the square root of 81, or 9. The diameter is twice the radius, so 18.反馈 收藏 ...
The area of a circle is:π (Pi) times the Radius squared:A = π r2 or, when you know the Diameter:A = (π/4) × D2 or, when you know the Circumference:A = C2 / 4πExample: What is the area of a circle with radius of 3 m ? Radius = r = 3 Area= π r2 = π× ...
A circle has a diameter of 10 cm. What's the area of the circle? A. 25π cm² B. 30π cm² C. 35π cm² D. 40π cm² 相关知识点: 试题来源: 解析 A。解析:圆的面积等于πr²,直径是 10 厘米,半径是 5 厘米,π×5²=25π 平方厘米。选项 B30π平方厘米错误,选项 C35...