Aaron. Area of a circle can be visualized & proved using two methods, namely. Determine the area of the shaded sector. The circle is divided into 16 equal sectors, and the sectors are arranged as shown in the fig. In the process, Diameter= 18, Radius(r)= (18)/2 :. You can enter the diameter and then compute radius and circumference in mils, inches, feet, yards, miles, millimeters, centimeters, meters and kilometers. How to Calculate Area. So instead of four pi, it is going to be two pi square units. d = 6 inches. Times the radius of the circle squared, and you say, well they gave us the diameter, what is the radius? Step-by-step explanation: The area of a circle is pi×radius^2. Square feet can also be expressed as ft 2 or sq. 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. Radius= 9 Now, Circumference (Perimeter) = ? (Answer) 0 0. - 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. 6 years ago. 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) Need a custom math course? The diameter of the circle will be 30 inches. Diameter of Circle. What is the area of a single slice? (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. 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. Well, the semicircle is half of the circle, so if I want the area of the semicircle, this is gonna be half this. 18*pi or 18*3.141592=56.55. Jamayaa Jamayaa Answer: 81. A circle is 0.7854 times as heavy as a square of the same size. What is the area of the circle? The area can be found by multiplying PI (3.14159) times the radius times the radius again. The perimeter is measured in units such as centimeters,meters, kilometers, inches, feet, yards, and miles. 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. New questions in Mathematics. Basically, a sector is the portion of a circle. So if you divide the given 18.84 by π, you get the diameter. As such, circumference of circle with radius 3 is 2xx3.1416xx3 or 6xx3.1416=18.8496~=18.85 , Note the number of square units it takes to fill it. alpha. 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. 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 . Lv 7. The formula to find the area of the segment is given below. 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. Area is the space inside the perimeter/boundary of space, and its symbol is (A). (diameter x pi = circumference). Visit https://www.MathHelp.com.This lesson covers the area of a circle. 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. Formulas, explanations, and graphs for each calculation. Find the area of a circle circumscribed about an equilateral triangle whose side is 18 inches long. 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. The area is measured in units such as square centimeters $(cm^2)$, square meters $(m^2)$, square kilometers $(km^2)$ etc. A=(3.14159)(9^2)=(3.14159)(81)=254.5. This is the diameter of a circle that corresponds to the specified area. 1 decade ago. 3. Also, assuming the same radius and diameter for a sphere, the surface area and volume of that sphere are returned. r=.5d=18/2=9. 10950 Lin-Valle Dr. Saint Louis, MO 63123 - (800) 462-7447 - … Area of a sector formula. 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. Add your answer and earn points. Plug that into the formula: A = π9² . Favorite Answer  Diameter is 18 units. Let's do another example. What is 9²?--> 9 * 9 = 81 . The circumference of a 4-inch diameter circle is: about 12.57 inches. It’s the size of a 2-dimensional surface and is measured in square units, for example, square feet. Circumference of circle with radius 3 is 18.85 Circumference of circle with radius r is 2pir, where pi=3.1416. Enter the area contained within a circle. NLattig8833 NLattig8833 Answer: 31.8 in^2. Lv 5. Rounded, the answer is 6.00 inches. 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 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) 1 See answer mcenaneykaitlyn3894 is waiting for your help. Henry knows that the circumference of a circle is 18 pi inches. Answer: 81π sq. Area = 81π cm². The radius is half the diameter (9 inches). What is the area of a circle, if the diameter is 18? … Answer Save. Circumference The distance around the outward boundary of a circle, expressed as a linear unit of measurement (millimeters, inches, etc.). The area of an oval is the longest diameter x the shortest x 0.7854. 10 Answers. (d)Diameter of a circle is always equal to two times of (r)radius. If M/N=20, what is the radius of the... See all questions in Connection to Areas Add your answer and earn points. A = 81π . 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) Circumference of a circle formula. Area of a Circle Segment Given the Central Angle. d = 18.84/ PI. Find the diameter of the circle 2 See answers tonb tonb The circumference is π times the diameter (2r). 2 See answers michellehu8888 michellehu8888 The area of the circle is 81 pi inches. 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. Area of Circle. A circular pizza that is 18 inches in diameter is cut into 8 equal slices. Step-by-step explanation: New questions in Mathematics. r = 9. The circumference of a circle is 18.84 inches. First we need to know that the area of a circle is a function of the radius. 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. 0 1. 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. 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) The formula for the area of a circle is: A = πr² . Area=Pi*r^2 =3.14*81 =254.34 sq units.  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. musiclover10045 musiclover10045 circumference = PI x D 18.84 = PI x D . A circle has an area of M cm^2 and a circumference of N cm. Thus, the area of a circle with a circumference of 18π centimeters is 81π squared centimeters. That's the area of the semicircle. The circumference can be found … Lv 5. Therefore radius r=9 units. Michael. 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