+.. |radius_constr.icon| image:: images/radius_constr.png
Radius constraint
=================
+
+Radius constraint fixes the radius of circle or arc.
+
+To create a Radius constraint in the active Sketch:
+
+#. select in the Main Menu *Sketch - > Radius* item or
+#. click |radius_constr.icon| **Radius** button in Sketch toolbar:
+
+Property panel:
+
+.. figure:: images/Radius_panel.png
+ :align: center
+
+.. |loc_left| image:: images/location_left.png
+.. |loc_auto| image:: images/location_automatic.png
+.. |loc_right| image:: images/location_right.png
+
+Input fields:
+
+- **Circle or Arc** is the circle or arc selected in the view;
+- **Value** is a radius of the selected object, could be modified to set the desirable value
+- **Text location** is a position of the radius value label relating to extension line (in the view)
+ | |loc_left| **Left** inserts text at the left of the radius extension line.
+ | |loc_auto| **Automatic** inserts text at the middle of the radius extension line if it has enough length, otherwise - to the left.
+ | |loc_right| **Right** inserts text to the right of the radius extension line.
+
+When circle or arc is selected, the radius value is displayed in the property panel and in the view.
+
+When creating the constraint, after selection of the circle or arc at the first time :
+
+- drag the radius presentation in the view to the desired position and click once;
+- set desirable radius value in the input field in the view and press **Enter** or just press **Enter** to keep the current radius.
+
+.. figure:: images/Radius_field_view.png
+ :align: center
+
+ Radius input in the view
+
+**TUI Command**:
+
+.. py:function:: Sketch_1.setRadius(CircleOrArc, Value)
+
+ :param object: Circle or arc.
+ :param real: Radius.
+ :return: Result object.
+
+Result
+""""""
+
+Created Radius appears in the view.
+
+.. figure:: images/Radius_res.png
+ :align: center
+
+ Radius created
+
+**See Also** a sample TUI Script of :ref:`tui_create_radius` operation.
