Explanation
In geometry, the circumference of a circle with radius (r) is defined by the following formula: =2πr
The Greek letter π (“pi”) represents the ratio of the circumference of a circle to its diameter. In Excel, π is represented in a formula with the PI function , which returns the number 3.14159265358979, accurate to 15 digits.
=PI() // returns 3.14159265358979
Therefore, the formula to calculate the circumference of a circle with a radius of 3 is:
=2*PI()*3 // returns 18.85
And the formula to calculate circumference based on the radius values in column B, is:
=2*PI()*B5
Explanation
The length of a line can be calculated with the distance formula, which looks like this:
Distance is the square root of the change in x squared plus the change in y squared, where two points are given in the form (x 1 , y 1 ) and (x 2 , y 2 ). The distance formula is an example of the Pythagorean Theorem applied, where the change in x and the change in y correspond to the two sides of a right triangle, and the hypotenuse is the distance being computed.
In Excel, the distance formula can be written with the exponent operator (^) and the SQRT function like this:
=SQRT((D5-B5)^2+(E5-C5)^2)
Following Excel’s order of operations , the change in x and the change in y is calculated, then squared, and the two results are added together and delivered to the SQRT function, which returns the square root of the sum as a final result:
=SQRT((D5-B5)^2+(E5-C5)^2)
=SQRT((6)^2+(8)^2)
=SQRT(36+64)
=SQRT(100)
=10
The POWER function can also be used instead of the exponent operator (^) like this:
=SQRT(POWER(D5-B5,2)+POWER(E5-C5,2))
with the same result.
