Plane Geometry

Plane Geometry

The URL below,

The three point circle

helps students grasp the principles of basic geometric construction. The tutorials also cover the objectives in Unit 2. This site is basically an animated step by step tutorial and covers the objectives set in the unit.

Basic plane geometry is covered during the early years of the secondary education. Several students who are preparing to sit for the SEC exam tend to remember topics covered during Form 4 and Form 5 whilst forgetting topics covered during the early years. Perhaps the following songs and videos will help them refresh their memory.


The following is a different method of constructing a regular pentagon.

Bisection of lines and angles, inscribed and circumscribed polygons, use of set squares to draw polygons.

A Circumscribed triangle

The triangle song

Extract from SEC 29 syllabus (2010)

Paper 1, Section 1

Plane Geometry

d) Triangles


-Construction of triangles, given:

  • 3 sides
  • 2 sides and their included angle
  • Base, one base angle and the length of the side opposite the base angle
  • Base and two base angles
  • The base of an equilateral triangle
  • The altitude of an equilateral triangle
  • Base and altitude of an isosceles triangle
  • Length of one side/angle and hypotenuse of a right angle triangle
  • 2 base angles and the altitude
  • Altitude and apex angle of an isosceles triangle
  • Perimeter and the ratio of the three sides
  • Perimeter and altitude of an isosceles triangle
  • Perimeter and the 2 base angles
  • Perimeter, base and base angle
  • Base angle, apex angle and altitude

The following are worked examples to illustrate each of the above sets of data.

Triangles 1-6
Triangles 7-12
Triangles 13-15

Internal and External Tangents to two unequal circles (notes prepared by Ms.Sylvana Zammit  Graphical Communication Teacher).

Geometric figures can be seen all around us as shown in the following video.

The Quadrilateral Song

The Circle Song