diff --git a/go.sum b/go.sum
index 15af9c4..1068d42 100644
--- a/go.sum
+++ b/go.sum
@@ -24,6 +24,7 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sirupsen/logrus v1.4.1/go.mod h1:ni0Sbl8bgC9z8RoU9G6nDWqqs/fq4eDPysMBDgk/93Q=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.1.1 h1:2vfRuCMp5sSVIDSqO8oNnWJq7mPa6KVP3iPIwFBuy8A=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
diff --git a/predicates.go b/predicates.go
index 3e64f38..5e25e93 100644
--- a/predicates.go
+++ b/predicates.go
@@ -85,3 +85,18 @@ func polygonToGeometry(geofence *geom.Polygon) *geos.Geometry {
 
 	return geos.Must(geos.NewPolygon(shellGeos, holes...))
 }
+
+func polygonToGeometryExample(geofence *geom.Polygon) *geos.Geometry {
+	// Convert the outer shell to geos format.
+	shell := geofence.LinearRing(0).Coords()
+	shellGeos := geomToGeosCoords(shell)
+
+	// Convert each hole to geos format.
+	numHoles := geofence.NumLinearRings() - 1
+	holes := make([][]geos.Coord, numHoles)
+	for i := 0; i < numHoles; i++ {
+		holes[i] = geomToGeosCoords(geofence.LinearRing(i).Coords())
+	}
+
+	return geos.Must(geos.NewPolygon(shellGeos, holes...))
+}
diff --git a/predicates_test.go b/predicates_test.go
index 1dfec6d..8ce1d52 100644
--- a/predicates_test.go
+++ b/predicates_test.go
@@ -56,3 +56,12 @@ func TestPredicates(t *testing.T) {
 		})
 	}
 }
+
+func TestPolygonToGeometryExample(t *testing.T) {
+	geofence := readFileAsGeometry(t, "testdata/regents.geojson")
+
+	geom := polygonToGeometryExample(geofence)
+	perimeterLength, err := geom.Length()
+	require.NoError(t, err)
+	assert.Equal(t, geofence.Length(), perimeterLength)
+}