Symbol  Format  Data 

π  Code Point 
U+03C0 
TeX 
\pi 

SVG 
The Greek small letter (pi) is used in trigonometry as a constant to represent a halfrotation around a circle in radians. The value of is approximately and appears in many math formulas and expressions. Read more…
The Greek letter τ (tau) is used in trigonometry as a constant to represent a full rotation around a circle in radians. The value of τ is approximately 6.28 and can be calculated by dividing any circle's circumference by its radius.
Geometry circle symbol.
The capital Greek letter Π (Pi) is visually very similar to the product symbol (∏) which is the dedicated symbol in math for the product operation.
The Greek letter π (pi) is a geometric constant approximately equal to 3.1416. Its value is equal to the length of any circle's circumference divided by its diameter.
The circumference of a circle is given the constant π (pi) multiplied by two times the radius of the circle.
The traditional formula for the area of a circle is given in terms of the geometric constant π (pi).
Radians are a unit that measures angle using the radius of a circle. One radian is equal to the amount of rotation required to travel the length of one radius along the circumference of the circle.