_PI - mkilgore/QB64pe GitHub Wiki

The _PI function returns π as a _FLOAT value with an optional multiplier parameter.

circumference = _PI[(multiplier)]

• Optional multiplier (2 * radius in above syntax) allows multiplication of the π value.

• Function can be used in to supply π or multiples in a program.
• Accuracy is determined by the return variable type AS SINGLE, DOUBLE or _FLOAT.
• The π value can also be derived using 4 * ATN(1) for a SINGLE value.

Example: Calculating the area of a circle using a SINGLE variable in this case.

radius = 5
circlearea = _PI(radius ^ 2)
PRINT circlearea

 78.53982

• _ATAN2, TAN
• ATN (arctangent)
• SIN, COS