Instruction

1

Suppose you want to buy a cover for the well, but the exact diameter is not known, but known components, only the circumference.

2

So, enter the names of the variables. Let d – diameter of the well, L is the circumference, n is the number PI, whose value is approximately equal to 3.14, R is the radius of the circle. The circumference (L) are known. Assume that it is equal to 628 cm.

3

Then to find the diameter (d) use the formula for the circumference of a circle: L=2PR, where R is the unknown variable, L=628 cm, and p=3,14. Now use the rule to find unknown multiplier: "to find an unknown multiplier, we need work divided by the known multiplier." Obtained: R=L/2P. The substitute values to the formula: R=628/2x3. 14. Obtained: R=628/6,28, R=100 cm.

4

After the radius of the circle was found (R=100 cm), use the following formula: the diameter of a circle (d) is equal to two radii of the circle (2R). Turns out: d=2R.

5

Now, to find the diameter, substitute into the formula d=2R values and calculate the result. Since the radius (R), is obtained: d=2x100, d=200 cm.