Incircle and excircles of a triangle polygon with any number of sides that has an inscribed circle—one that is tangent to each side—is called a tangential polygon. Incircle and excircles of a triangle In geometry, the incircle or inscribed circle of a triangle is the largest circle contained in the triangle; it touches (is tangent to) the three sides. The center of the incircle is a triangle center called the triangle's incenter. An excircle or escribed circle of the triangle is a circle lying outside the triangle, tangent to one of its sides and tangent to the extensions of the other two. Every triangle has three
Slotted line also used, with a movable insulated probe inserted into a longitudinal slot cut into the line. In a co-axial slotted line, the slot is cut into the outer conductor of the line. The probe is inserted past the outer conductor, but not so far that it touches the inner conductor. In a rectangular waveguide, the slot is usually cut along the centre of the broad wall of the waveguide. Circular waveguide slotted lines are also possible. Slotted lines are relatively cheap and can perform many of the measurements done by more expensive equipment such as network analysers. However, slotted line