Some mathematical problems that feature pi are the area of a circle, a circle's circumference, arc length and the different surface area and volume formulas for a cone, sphere and cylinder. In mathematics, the ratio between a circle's circumference and diameter is given as pi.Know More
While the circle's circumference is given by the formula 2 x radius x pi, its area formula is pi x radius squared. Similarly, many of the area and volume formulas for different geometric solids were formulated with pi as a term in them. For example, the area of a sphere is 4 x pi x radius squared, and its volume formula is 4/3 x pi x radius cubed.
The history of pi dates back to the ancient Babylonians and Egyptians. Babylonians estimated pi as 3.125, and the Egyptians approximated pi to be 3.1605. However, it was the Greek mathematician Archimedes that calculated pi to be between 223/71 and 22/7. A general estimate for pi is 22/7 or 3.14.
In 1706, William Jones was the first to introduce a Greek letter for pi, which was later adopted by the mathematician Euler to represent the ratio between a circle's circumference to its area. Later mathematicians extended the number of decimal places in this irrational number through rigorous calculations. In the computer age, pi has been estimated to its two-quadrillionth digit.Learn More
A factor is a number or expression that divides another number or expression evenly without a remainder. For instance, two, four, five and 10 are factors of 20 because 20 can be divided by all those smaller numbers an exact number of times. Prime numbers are positive integers greater than one that have exactly two factors. A composite number has more than two factors.Full Answer >
Radians measure angles as the arc length of a circle subtended by an angle, divided by the radius of the circle. Each radian is equal to approximately 57.3 degrees, and there are approximately 6.28 radians in a full circle.Full Answer >
A mathematical verbal expression is a translation into words of an algebraic expression that can consist of different operations, numbers and variables. An example of this is translating the mathematical equation or phrase "90 - 4(a + 8)" to the verbal expression "90 decreased by 4 times the sum of a number "a" and 8."Full Answer >
The circumference of a circle is the line that makes up the edge of the circle, such that every point on the line is equidistant from the center. It is different from the diameter because the diameter is a line that passes through the center of the circle and has endpoints on opposite sides of the circumference.Full Answer >