Tangential polygon

In <a href="/facts/Euclidean_geometry/V6cTcoCy">Euclidean geometry</a>, a tangential polygon, also known as a circumscribed polygon, is a <a href="/facts/Convex_polygon/7x35w610">convex polygon</a> that contains an <a href="/facts/Inscribed_figure/ltbko1Eh">inscribed circle</a> (also called an incircle). This is a circle that is <a href="/facts/Tangent/sF0jH3EI">tangent</a> to each of the polygon's sides. The <a href="/facts/Dual_polygon/mbR8QK0n">dual polygon</a> of a tangential polygon is a <a href="/facts/Cyclic_polygon/RafYT4am">cyclic polygon</a>, which has a <a href="/facts/Circumscribed_circle/RafYT4am">circumscribed circle</a> passing through each of its <a href="/facts/Vertex_(geometry)/ID3cea9z">vertices</a>.
All <a href="/facts/Triangle/cRXUwsMn">triangles</a> are tangential, as are all <a href="/facts/Regular_polygon/ws89Nhpt">regular polygons</a> with any number of sides. A well-studied group of tangential polygons are the <a href="/facts/Tangential_quadrilateral/JBdfotIx">tangential quadrilaterals</a>, which include the <a href="/facts/Rhombi/T4pU50GF">rhombi</a> and <a href="/facts/Kite_(geometry)/PRcvPntl">kites</a>.

Tangential polygon open-in-new

Tangential polygon