diff --git a/demo/maps/src/jvmMain/kotlin/Main.kt b/demo/maps/src/jvmMain/kotlin/Main.kt
index a70da7c..e790431 100644
--- a/demo/maps/src/jvmMain/kotlin/Main.kt
+++ b/demo/maps/src/jvmMain/kotlin/Main.kt
@@ -1,4 +1,3 @@
-// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 import androidx.compose.desktop.ui.tooling.preview.Preview
 import androidx.compose.material.MaterialTheme
 import androidx.compose.material.icons.Icons
@@ -23,6 +22,7 @@ import kotlinx.coroutines.launch
 import java.nio.file.Path
 import kotlin.math.PI
 import kotlin.random.Random
+import center.sciprog.maps.coordinates.kilometers
 
 private fun GeodeticMapCoordinates.toShortString(): String =
     "${(latitude.degrees.value).toString().take(6)}:${(longitude.degrees.value).toString().take(6)}"
@@ -91,7 +91,7 @@ fun App() {
                 drawLine(start = Offset(-10f, 10f), end = Offset(10f, -10f), color = Color.Red)
             }
 
-            arc(pointOne, Distance(10.0), 0f, PI)
+            arc(pointOne, 10.0.kilometers, 0f, PI)
 
             line(pointOne, pointTwo, id = "line")
             text(pointOne, "Home", font = { size = 32f })
diff --git a/maps-kt-core/src/commonMain/kotlin/center/sciprog/maps/coordinates/angles.kt b/maps-kt-core/src/commonMain/kotlin/center/sciprog/maps/coordinates/Angle.kt
similarity index 100%
rename from maps-kt-core/src/commonMain/kotlin/center/sciprog/maps/coordinates/angles.kt
rename to maps-kt-core/src/commonMain/kotlin/center/sciprog/maps/coordinates/Angle.kt
diff --git a/maps-kt-core/src/commonMain/kotlin/center/sciprog/maps/coordinates/Distance.kt b/maps-kt-core/src/commonMain/kotlin/center/sciprog/maps/coordinates/Distance.kt
index 5fc1349..48d3445 100644
--- a/maps-kt-core/src/commonMain/kotlin/center/sciprog/maps/coordinates/Distance.kt
+++ b/maps-kt-core/src/commonMain/kotlin/center/sciprog/maps/coordinates/Distance.kt
@@ -3,10 +3,13 @@ package center.sciprog.maps.coordinates
 import kotlin.jvm.JvmInline
 
 @JvmInline
-public value class Distance(public val kilometers: Double) : Comparable<Distance> {
+public value class Distance internal constructor(public val kilometers: Double) : Comparable<Distance> {
     override fun compareTo(other: Distance): Int = this.kilometers.compareTo(other.kilometers)
 }
 
+public val Number.kilometers: Distance get() = Distance(toDouble())
+public val Number.meters: Distance get() = Distance(toDouble() / 1000)
+
 public operator fun Distance.div(other: Distance): Double = kilometers / other.kilometers
 
 public operator fun Distance.plus(other: Distance): Distance = Distance(kilometers + other.kilometers)