Vocabulary (Basic Geometry)

English terms related to Basic Geometry:

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, octogon, 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.

Symmetry

  • Symmetric shapes.
  • Axis of symmetry.