How do you convert the diameter of a circle to square feet?

Answer 1

You don'tPerhaps your question is very poorly articulated.

You don't "convert" a diameter to "square feet." You calculate a circle's area (in square feet) if you know its diameter (in feet) and the formula for the area of a circle.

The area of circle is given by the formula A = (Pi)r2, where r is the radius of the circle. Note that the radius is one half the diameter: r = d/2.

We can then derive a formula for area as a function of the diameter:

A = (Pi)r2 = (Pi)(d/2)2 = (Pi)d2/4 or (1/4)(Pi)d2.

When using the formulas, you must be certain that your units are consistent. If your diameter is in feet, then your answer will be in square feet.

Note that you can use Pi = 3.14 for most routine calculations.

Actually, you can use a diameter in inches and get an area in square feet. The constant is 0.005454. So, the area equation is converted to look like this

A=0.005454d2

you do not have to get an answer in the same units

also, the same applies for the metric system

A=0.0000785d2

for this, you can put in a diameter in centimeters and get square meters

So sorry man, but you can indeed get an area that is in a different unit.

Addenda

The fact remains that the diameter of a circle is a linear measurement and cannot be converted to an area or square measurement. Knowing the diameter you can find the area of the circle and using various manipulations convert it to the desired system of units.