Congruent Polygons are polygons that have the same shape and size. When two polygons are congruent, one of the polygons can be placed exactly over the other by sliding, flipping or turning.

Congruent Polygons

Congruence shapes find application widely in machine designing and manufacturing.  Equilateral triangles , squares and regular hexagons are congruent regular polygons which tessellate around a vertex to form patterns. Congruent Regular Polygons also make the faces of regular polyhedra which are called Platonic solids. The commonly known Platonic solids are Tetrahedron and Hexahedron. A Tetrahedron is made up of four congruent equilateral triangles and six congruent squares constitute a Hexahedron.

Two polygons are congruent if the vertices of one polygon bears a one to one correspondence to the regular Pole vertices of the other polygon and the corresponding angles and corresponding sides so formed are congruent. In simple words "Corresponding parts of congruent polygons are congruent."

Congruent polygons are named by placing the corresponding vertices in the same order for both the polygons.

Congruent Polygons Definition

Given that, ABCDE ≅ FGHIJ     then the corresponding vertices are
A ↔ F
B ↔ G
C ↔ H
D ↔ I
E ↔ J
The angles named after corresponding vertices are the corresponding angles and they are congruent.
∠A ≅ ∠F,   ∠B ≅ ∠G,    ∠C  ≅ ∠H,     ∠D ≅ ∠I    and ∠E ≅ ∠J.

The congruent corresponding sides are named combining corresponding vertices in the same order.  
AB ≅  FGBCGHCDHIDEIJ   and EAJF.