Repo created

libs/geometry/area_on_earth.hpp

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+#pragma once
+
+#include "geometry/latlon.hpp"
+
+namespace ms
+{
+// Returns area of triangle on earth.
+double AreaOnEarth(LatLon const & ll1, LatLon const & ll2, LatLon const & ll3);
+
+// Area of the spherical cap that contains all points
+// within the distance |radius| from an arbitrary fixed point, measured
+// along the Earth surface.
+// In particular, the smallest cap spanning the whole Earth results
+// from radius = pi*EarthRadius.
+// For small enough radiuses, returns the value close to pi*|radius|^2.
+double CircleAreaOnEarth(double radius);
+}  // namespace ms