diff --git a/math.go b/math.go
index 6fc6ab1..6f15631 100644
--- a/math.go
+++ b/math.go
@@ -6,6 +6,9 @@ func emulate32(f float32, fn func(float64) float64) float32 {
 	return float32(fn(float64(f)))
 }
 
+// Pi constant https://oeis.org/A000796
+const Pi = math.Pi
+
 // Abs returns the absolute value.
 func Abs(f float64) float64 {
 	return math.Abs(f)