Area = (π)(9 cm)². Rounded, the answer is 6.00 inches. 10 Answers. You can enter the diameter and then compute radius and circumference in mils, inches, feet, yards, miles, millimeters, centimeters, meters and kilometers. Given: radius of a circle = 15 inches Required to find - diameter Solution: d = 2r d = 2x15 d=30 Therefore the diameter of the given circle will be 30 inches. A circle of radius = 6 or diameter = 12 or circumference = 37.7 inches has an area of: 7.29676 × 10-8 square kilometers (km²); 0.0729676 square meters (m²) 729.676 square centimeters (cm²) To find area from the circle's diameter: a = \pi (d/2)^2. Formulas, explanations, and graphs for each calculation. inches. Note the number of square units it takes to fill it. With this semicircle area calculator, you can quickly find the area of half of a circle.What is more, the tool also doubles as a semicircle perimeter calculator, so inputting radius or diameter will help you find the basic features of the shape in the blink of an eye.In the article below, we provide the semicircle definition and explain how to find the perimeter and area of a semicircle. That's the area of the semicircle. What is 9²?--> 9 * 9 = 81 . Area of a circle can be visualized & proved using two methods, namely. 10950 Lin-Valle Dr. Saint Louis, MO 63123 - (800) 462-7447 - … r = 9. P.S. Also, assuming the same radius and diameter for a sphere, the surface area and volume of that sphere are returned. musiclover10045 musiclover10045 circumference = PI x D 18.84 = PI x D . Visit https://www.MathHelp.com.This lesson covers the area of a circle. Jamayaa Jamayaa Answer: 81. Area of Circle. Henry knows that the circumference of a circle is 18 pi inches. Solution for A circle has an 18-inch radius and a shaded sector with a central angle of 50°. Area = 81π cm². Area of a sector formula. Diameter of Circle. Determining the circle’s area using rectangles; Determining the circle’s area using triangles; Let us understand both the methods one-by-one-Using Areas of Rectangles. 1 See answer mcenaneykaitlyn3894 is waiting for your help. Area of a triangle calculation using all different rules, side and height, SSS, ASA, SAS, SSA, etc. So if you divide the given 18.84 by π, you get the diameter. Radius= 9 Now, Circumference (Perimeter) = ? The circumference of a circle is calculated using the formula: 2 x π x radius, where π is a mathematical constant, equal to about 3.14159.It was originally defined as the ratio of a circle's circumference to its diameter (see second formula below on why) and appears in many formulas in mathematics, physics, and everyday life. Let's do another example. Area is the space inside the perimeter/boundary of space, and its symbol is (A). Basically, a sector is the portion of a circle. Add your answer and earn points. The circumference of a 4-inch diameter circle is: about 12.57 inches. The diameter of the circle will be 30 inches. Relevance. NLattig8833 NLattig8833 Answer: 31.8 in^2. The radius is half the diameter (9 inches). Michael. 3. (Answer) 0 0. If the diameter is 18 inches, what is the radius? A circle of radius = 2.998 or diameter = 5.997 or circumference = 18.84 centimeters has an area of: 2.825 × 10-9 square kilometers (km²); 0.002825 square meters (m²) 28.25 square centimeters (cm²) A = 81π . Thus, the area of a circle with a circumference of 18π centimeters is 81π squared centimeters. Step-by-step explanation: New questions in Mathematics. (18(π) cm) = 2(π)r (18(π) cm)/(2(π)) = r. 9 cm = r. Now since we found that the value of radius r is 9 cm, we can solve for the area of the circle using the formula mentioned early: Area = (π)r². In geometry, the area enclosed by a circle of radius r is πr 2.Here the Greek letter π represents the constant ratio of the circumference of any circle to its diameter, approximately equal to 3.14159.. One method of deriving this formula, which originated with Archimedes, involves viewing the circle as the limit of a sequence of regular polygons. The circle is divided into 16 equal sectors, and the sectors are arranged as shown in the fig.  2020/10/08 18:09 Male / Under 20 years old / Elementary school/ Junior high-school student / Useful / Purpose of use Helped me with finding areas of a circle. Square feet can also be expressed as ft 2 or sq. 1 decade ago. If M/N=20, what is the radius of the... See all questions in Connection to Areas The area can be found by multiplying PI (3.14159) times the radius times the radius again. Lv 7. According to the formula, Perimeter= 2 xx (22)/7 xx r Taking the equation, Perimeter= 2 xx (22)/7 xx r rArr2 xx (22)/7 xx 9 rArr (396)/7 rArr 56.57142857 rArr 56.57 Let's hope this helps you:) Geometry . Answer: 81π sq. The area, A of the circle with radius r is given by $$A$$ = $$π~r^2$$ Definition 3: The portion of the circle enclosed by two radii and the corresponding arc is known as the sector of a circle. It’s the size of a 2-dimensional surface and is measured in square units, for example, square feet. 6 years ago. Times the radius of the circle squared, and you say, well they gave us the diameter, what is the radius? A circle of radius = 5 or diameter = 10 or circumference = 31.42 inches has an area of: 5.06709 × 10-8 square kilometers (km²); 0.0506709 square meters (m²) 506.709 square centimeters (cm²) d = 18.84/ PI. A circle of radius = 12 or diameter = 24 or circumference = 75.4 inches has an area of: 2.9187 × 10-7 square kilometers (km²); 0.29187 square meters (m²) 2918.7 square centimeters (cm²) 800 Square Inches to Circular Inches = 1018.5916: 20 Square Inches to Circular Inches = 25.4648: 900 Square Inches to Circular Inches = 1145.9156: 30 Square Inches to Circular Inches = 38.1972: 1,000 Square Inches to Circular Inches = 1273.2395: 40 Square Inches to Circular Inches = 50.9296: 10,000 Square Inches to Circular Inches = 12732.3954 The formula to find the area of the segment is given below. The area is measured in units such as square centimeters $(cm^2)$, square meters $(m^2)$, square kilometers $(km^2)$ etc. Circumference The distance around the outward boundary of a circle, expressed as a linear unit of measurement (millimeters, inches, etc.). Circumference of a circle formula. 2 See answers michellehu8888 michellehu8888 The area of the circle is 81 pi inches. Definition: The number of square units it takes to fill a segment of a circle Try this Drag one of the orange dots that define the endpoints of the segment. 1 See answer nafissmith23 is waiting for your help. What is the area of a circle, if the diameter is 18? Step-by-step explanation: The area of a circle is pi×radius^2. 0 1. - 8929571 nafissmith23 nafissmith23 02/27/2018 Mathematics College Find the area of a circle circumscribed about an equilateral triangle whose side is 18 inches long. A=(3.14159)(9^2)=(3.14159)(81)=254.5. Add your answer and earn points. Therefore radius r=9 units. A circle is 0.7854 times as heavy as a square of the same size. The formula for the area of a circle is: A = πr² . How to Calculate Area. But instead of a 16 inch diameter, it's now an 18 inch diameter circle. In the process, Diameter= 18, Radius(r)= (18)/2 :. alpha. A circular pizza that is 18 inches in diameter is cut into 8 equal slices. Circumference of circle with radius 3 is 18.85 Circumference of circle with radius r is 2pir, where pi=3.1416. An easy to use, free area calculator you can use to calculate the area of shapes like square, rectangle, triangle, circle, parallelogram, trapezoid, ellipse, octagon, and sector of a circle. A circle has an area of M cm^2 and a circumference of N cm. The formula for the area of a sector is (angle / 360) x π x radius 2.The figure below illustrates the measurement: As you can easily see, it is quite similar to that of a circle, but modified to account for the fact that a sector is just a part of a circle. Determine the area of the shaded sector. Since the formula for the area of a circle squares the radius, the area of the larger circle is always 4 (or 2 2) times the smaller circle.Think about it: You are doubling a number (which means ×2) and then squaring this (ie squaring 2) -- which leads to a new area that is four times the smaller one. Find the area of a circle circumscribed about an equilateral triangle whose side is 18 inches long. Need a custom math course? New questions in Mathematics. d = 6 inches. Area of a Circle Segment Given the Central Angle. (diameter x pi = circumference). Aaron. And so when we think about area, we know that the area of a circle, the area of a circle is equal to pi times the radius of the circle squared. Enter any of the four circle values, area, radius, diameter or circumference, click on Calculate and the other three values are returned in full (up to 18 decimal places) and maximum 3 decimal place rounded values. This is the diameter of a circle that corresponds to the specified area. Lv 5. The circumference of a circle is 18.84 inches. Area=Pi*r^2 =3.14*81 =254.34 sq units. Plug that into the formula: A = π9² . What is the area of a single slice? Using the Diameter Calculator. The perimeter is measured in units such as centimeters,meters, kilometers, inches, feet, yards, and miles. Well, the semicircle is half of the circle, so if I want the area of the semicircle, this is gonna be half this. The area of an oval is the longest diameter x the shortest x 0.7854. 1 decade ago. Find the diameter of the circle 2 See answers tonb tonb The circumference is π times the diameter (2r). Lv 5. 18*pi or 18*3.141592=56.55. Favorite Answer  Diameter is 18 units. (d)Diameter of a circle is always equal to two times of (r)radius. It would hence be right to say that a semi-circle or a quarter-circle is a sector of the given circle. First we need to know that the area of a circle is a function of the radius. Enter the area contained within a circle. r=.5d=18/2=9. The circumference can be found … As such, circumference of circle with radius 3 is 2xx3.1416xx3 or 6xx3.1416=18.8496~=18.85 , C x 34 = Show Your work WHY AM I DOING SCHOOL AT 2AM -.- DAAAAAANG, YALL SMART :O CAN U HELP WITH THIS ONE THOUGH? So instead of four pi, it is going to be two pi square units. 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