diff --git a/Polyhedron/demo/Polyhedron/Polyhedron_demo_selection_plugin.cpp b/Polyhedron/demo/Polyhedron/Polyhedron_demo_selection_plugin.cpp
index 31a1554e3ec..0195666dec1 100644
--- a/Polyhedron/demo/Polyhedron/Polyhedron_demo_selection_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Polyhedron_demo_selection_plugin.cpp
@@ -98,6 +98,8 @@ public:
     connect(ui_widget.Keep_connected_components_button, SIGNAL(clicked()), this, SLOT(on_Keep_connected_components_button_clicked()));
     connect(ui_widget.Dilate_erode_button, SIGNAL(clicked()), this, SLOT(on_Dilate_erode_button_clicked()));
     connect(ui_widget.Create_polyhedron_item_button, SIGNAL(clicked()), this, SLOT(on_Create_polyhedron_item_button_clicked()));
+    connect(ui_widget.Select_sharp_edges_button, SIGNAL(clicked()), this, SLOT(on_Select_sharp_edges_button_clicked()));
+
     QObject* scene = dynamic_cast<QObject*>(scene_interface);
     if(scene) { 
       connect(scene, SIGNAL(itemAboutToBeDestroyed(Scene_item*)), this, SLOT(item_about_to_be_destroyed(Scene_item*)));
@@ -298,6 +300,18 @@ public Q_SLOTS:
       print_message("Error: polyhedron item is not created!");
     }
   }
+
+  void on_Select_sharp_edges_button_clicked() {
+    Scene_polyhedron_selection_item* selection_item = get_selected_item<Scene_polyhedron_selection_item>();
+    if (!selection_item) {
+      print_message("Error: there is no selected polyhedron selection item!");
+      return;
+    }
+
+    double angle = ui_widget.Sharp_angle_spinbox->value();
+    selection_item->select_sharp_edges(angle);
+  }
+
   void on_Dilate_erode_button_clicked() {
     Scene_polyhedron_selection_item* selection_item = get_selected_item<Scene_polyhedron_selection_item>();
     if(!selection_item) {
diff --git a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h
index 5d281d3b18d..c48c85df38f 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h
@@ -13,6 +13,7 @@
 #include <CGAL/Polygon_mesh_processing/orient_polygon_soup.h>
 #include <CGAL/Polygon_mesh_processing/polygon_soup_to_polygon_mesh.h>
 #include <CGAL/Polygon_mesh_processing/connected_components.h>
+#include "Polyhedron_demo_detect_sharp_edges.h"
 
 #include <fstream>
 #include <boost/foreach.hpp>
@@ -20,6 +21,7 @@
 #include <boost/property_map/vector_property_map.hpp>
 
 #include <CGAL/boost/graph/selection.h>
+#include <CGAL/boost/graph/graph_traits_Polyhedron_3.h>
 
 namespace PMP = CGAL::Polygon_mesh_processing;
 
@@ -705,6 +707,34 @@ public:
     return out->size_of_vertices() > 0;
   }
 
+  struct Is_sharp_edge_property_map
+  {
+    friend bool get(Is_sharp_edge_property_map,
+                    Polyhedron::Halfedge_handle h)
+    {
+      return h->is_feature_edge();
+    }
+    friend void put(Is_sharp_edge_property_map,
+                    Polyhedron::Halfedge_handle h,
+                    bool b)
+    {
+      h->set_feature_edge(b);
+    }
+  };
+
+  void select_sharp_edges(const double angle)
+  {
+    CGAL::detect_sharp_edges(polyhedron(), angle);
+
+    Is_sharp_edge_property_map is_sharp;
+    BOOST_FOREACH(edge_descriptor e, edges(*polyhedron()))
+    {
+      Polyhedron::Halfedge_handle h = halfedge(e, *polyhedron());
+      if (get(is_sharp, h))
+        selected_edges.insert(e);
+    }
+  }
+
   void changed_with_poly_item() {
     // no need to update indices
     poly_item->changed();
diff --git a/Polyhedron/demo/Polyhedron/Selection_widget.ui b/Polyhedron/demo/Polyhedron/Selection_widget.ui
index d178b56ad88..fce61d9f557 100644
--- a/Polyhedron/demo/Polyhedron/Selection_widget.ui
+++ b/Polyhedron/demo/Polyhedron/Selection_widget.ui
@@ -180,6 +180,93 @@
       </layout>
      </widget>
     </item>
+    <item>
+     <widget class="QGroupBox" name="groupBox_3">
+      <property name="title">
+       <string/>
+      </property>
+      <widget class="QWidget" name="horizontalLayoutWidget">
+       <property name="geometry">
+        <rect>
+         <x>10</x>
+         <y>10</y>
+         <width>291</width>
+         <height>80</height>
+        </rect>
+       </property>
+       <layout class="QHBoxLayout" name="horizontalLayout_7">
+        <item>
+         <widget class="QScrollArea" name="scrollArea">
+          <property name="widgetResizable">
+           <bool>true</bool>
+          </property>
+          <widget class="QWidget" name="scrollAreaWidgetContents">
+           <property name="geometry">
+            <rect>
+             <x>0</x>
+             <y>0</y>
+             <width>287</width>
+             <height>76</height>
+            </rect>
+           </property>
+           <widget class="QPushButton" name="Select_sharp_edges_button">
+            <property name="geometry">
+             <rect>
+              <x>210</x>
+              <y>30</y>
+              <width>75</width>
+              <height>23</height>
+             </rect>
+            </property>
+            <property name="text">
+             <string>Select</string>
+            </property>
+           </widget>
+           <widget class="QSpinBox" name="Sharp_angle_spinbox">
+            <property name="geometry">
+             <rect>
+              <x>121</x>
+              <y>30</y>
+              <width>81</width>
+              <height>22</height>
+             </rect>
+            </property>
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="maximum">
+             <number>180</number>
+            </property>
+            <property name="value">
+             <number>60</number>
+            </property>
+           </widget>
+           <widget class="QLabel" name="label_4">
+            <property name="geometry">
+             <rect>
+              <x>5</x>
+              <y>30</y>
+              <width>111</width>
+              <height>20</height>
+             </rect>
+            </property>
+            <property name="text">
+             <string>Sharp edges angle:</string>
+            </property>
+            <property name="alignment">
+             <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+            </property>
+           </widget>
+          </widget>
+         </widget>
+        </item>
+       </layout>
+      </widget>
+     </widget>
+    </item>
     <item>
      <widget class="QGroupBox" name="groupBox_4">
       <property name="title">
@@ -277,19 +364,6 @@
       </property>
      </widget>
     </item>
-    <item>
-     <spacer name="verticalSpacer">
-      <property name="orientation">
-       <enum>Qt::Vertical</enum>
-      </property>
-      <property name="sizeHint" stdset="0">
-       <size>
-        <width>20</width>
-        <height>40</height>
-       </size>
-      </property>
-     </spacer>
-    </item>
    </layout>
   </widget>
  </widget>