Strong mode and linter clean-up for plane
diff --git a/lib/src/vector_math/plane.dart b/lib/src/vector_math/plane.dart
index b719ac4..a8b89c9 100644
--- a/lib/src/vector_math/plane.dart
+++ b/lib/src/vector_math/plane.dart
@@ -11,25 +11,26 @@
   /// Find the intersection point between the three planes [a], [b] and [c] and
   /// copy it into [result].
   static void intersection(Plane a, Plane b, Plane c, Vector3 result) {
-    final cross = new Vector3.zero();
+    final Vector3 cross = new Vector3.zero();
 
     b.normal.crossInto(c.normal, cross);
 
-    final f = -a.normal.dot(cross);
+    final double f = -a.normal.dot(cross);
 
-    final v1 = cross.scaled(a.constant);
+    final Vector3 v1 = cross.scaled(a.constant);
 
     c.normal.crossInto(a.normal, cross);
 
-    final v2 = cross.scaled(b.constant);
+    final Vector3 v2 = cross.scaled(b.constant);
 
     a.normal.crossInto(b.normal, cross);
 
-    final v3 = cross.scaled(c.constant);
+    final Vector3 v3 = cross.scaled(c.constant);
 
-    result.x = (v1.x + v2.x + v3.x) / f;
-    result.y = (v1.y + v2.y + v3.y) / f;
-    result.z = (v1.z + v2.z + v3.z) / f;
+    result
+      ..x = (v1.x + v2.x + v3.x) / f
+      ..y = (v1.y + v2.y + v3.y) / f
+      ..z = (v1.z + v2.z + v3.z) / f;
   }
 
   Vector3 get normal => _normal;
@@ -63,12 +64,10 @@
   }
 
   void normalize() {
-    var inverseLength = 1.0 / normal.length;
+    final double inverseLength = 1.0 / normal.length;
     _normal.scale(inverseLength);
     _constant *= inverseLength;
   }
 
-  double distanceToVector3(Vector3 point) {
-    return _normal.dot(point) + _constant;
-  }
+  double distanceToVector3(Vector3 point) => _normal.dot(point) + _constant;
 }