GEOMETRY VOCABULARY

The basics

Point.
Line.
Ray.
Line segment.

Lines

Parallel lines.
Intersecting lines.
Perpendicular lines.

Angles

Vertex.
Sides.
Acute angle.
Right angle.
Obtuse angle.
Stright angle.
Reflex angle.
Complementary angles.
Suplementary angles.
Degree.
Opposite angles.
Congruent angles.

Circle and circumference

Centre.
Radius.
Diametre.
Arc.
Chord.
Central angle.
Inscribed angle.
Tangent line.
Intersecting line.
No intersection line or outside line.

Special lines

Perpendicular bisector.
Angle bisector.

Geometric shapes

Polygon: triangle, quadrilateral, pentagon, hexagon, heptagon, octagon, nonagon, decagon...
Regular polygon.
Vertices and sides.

Triangles

Types of triangles by angles:
Acute triangle.
Right triangle.
Obtuse triangle.
Types of triangles by sides:
Equilateral triangle.
Isosceles triangle.
Scalene triangle.

Quadrilaterals

Square.
Rectangle.
Parallelogram.
Rhombus.
Kite.
Trapezium.,