Circle - the closed curve which points are equidistanted from its center. The main characteristics of a circle are the radius and diameter connected among themselves both visually and arithmetically.
Instruction
1. Diameter is the piece which is connecting two any points on a circle and passing through its center. Therefore if diameter needs to be found, knowing the radius of this circle, then it is necessary to increase numerical value of radius by two and to measure the found value in the same units, as radius. Example: Radius of a circle is 4 centimeters. To find diameter of this circle. Decision: Diameter is equal 4 sm*2=8 see the Answer: 8 centimeters.
2. If the dimeter needs to be found through circle length, then it is necessary to work using the first step. There is a formula for calculation of length of a circle: l=2pr, where circle l-length, the 2nd constant, p - the number equal 3.14; R - circle radius. Knowing that diameter is a double radius, the above-stated formula can be written down in a look: l= pd, where D - diameter.
3. To express diameter of a circle from this formula: D=l/item. And to substitute in it all known sizes, having calculated the linear equation with one unknown. Example: To find diameter of a circle if its length is 3 meters. Decision: diameter is equal 3/3 = to 1 m. Answer: diameter is equal to one meter.