1) From point P, use the Circle with Center through Point tool[icon]/images/ggb/toolbar/mode_circle2.png[/icon] to create a circle centered at point P that intersects the dotted line in two place.[br]2) Use the Intersect tool[icon]/images/ggb/toolbar/mode_intersect.png[/icon] to mark the points where the circle intersects the dotted line.[br]3) Use the Polygon tool[icon]/images/ggb/toolbar/mode_polygon.png[/icon] to create a triangle with vertices at the three points shown.[br]4) Use the Distance tool[icon]/images/ggb/toolbar/mode_distance.png[/icon] and the Angle Measure tool[icon]/images/ggb/toolbar/mode_angle.png[/icon] to verify that the triangle is isosceles.