To determine the area of a circle from its diameter, divide the diameter by two, square it and multiply by π. The formula for calculating the area of a circle is: A = πr^{2}, where r is the radius of the circle.
Continue ReadingMathematician Archimedes (287-212 B.C.E) was first to calculate the area of a circle. He recognized that the area of a hexagon inscribed inside a circle was a gross approximation of the area of the circle. The area of a hexagon is calculated by breaking it into six equilateral triangles where the base of the triangle is the length of one side of the hexagon and the other two legs of the triangle are equal to the radius of the circle.
Archimedes realized that as the number of sides on a polygon approaches infinity, the area is equal to the square of the radius of the circle times a constant, to which he assigned the Greek letter π.
Learn more about MeasurementsOne can calculate the diameter of a circle mathematically if the circumference or the area of the circle is known. If the location of the center of the circle is known, then the circle's diameter can be measured with a ruler passing through the center.
Full Answer >If the circumference or the area of a circle is known, pi can be used to find the diameter and the radius of that circle. Likewise, if the radius or diameter is known, pi can be used to find out the circumference or the area.
Full Answer >The total area of 12 millimeters by 10 millimeters is 120 square millimeters, assuming that this is an enclosed area with two sides of 12 millimeters and two sides of 10 millimeters. The formula for finding the area of a rectangle is length times width.
Full Answer >To calculate the square footage of a square or rectangle, measure the length and width of the area in feet, then multiply length by width to determine square footage. Different formulas are used to calculate the square footage of different shapes.
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