Experiment set GEOMETRY 1



The geometry topics of this experiment set are inter-year topics: the first chapters are designed for introductory lessons in secondary school, while the following ones are for intermediate level. However, the order of the individual chapters does not need to be followed strictly for understanding.

The topics are:

  • Angles: The introduction is done through an ungraduated angle model. Subsequently, students use a newly developed protractor, where misreading is prevented by the arrangement and position of the numerical values. With suitable triangles, the class can easily recognize the properties of adjacent, vertical, and complementary angles, as well as the angle sum in a triangle.
  • Area: The equations for the areas of special quadrilaterals are developed by adding or rearranging partial areas. They can independently find the equations for the area of a triangle by applying already known methods. Similar triangles help in the use of the intercept theorems, as well as the trigonometric functions of the right triangle.
  • Right triangle: Using an illustrative model, students discover the Thales theorem. They prove the Pythagorean theorem and the area theorems of Euclid with triangles, squares, and rectangles made of high-quality coloured acrylic glass. Certain connections can be assumed due to the use of the same colours.
  • Intercept theorems and trigonometric functions: Similar triangles help in the use of the intercept theorems, as well as the trigonometric functions of the right-angled triangle.


25.01.10   Storage case (small)

25.01.20   Lid with handle

91.02.00   Inlay with cut-outs

91.03.00   Large right-angled triangle (4 pieces)

91.04.00   Small right-angled triangle (4 pieces)

91.05.00   Isosceles right-angled triangle (4 pieces)

91.06.00   Equilateral triangle (2 pieces)

91.07.00   Rectangle 80/45

91.08.00   Rectangle 25/80

91.09.00   Rectangle125/45

91.11.00   Plastic box with 30 unit squares

01.13.50   Storage pin G1

91.13.00   Square 75/75

91.14.00   Square 80/80

91.15.00   Square 100/100

13.16.00   Plastic plate RA (3 pieces)

91.17.50   Thales model

91.18.00   Rectangle 60/30 (2 Stück)

91.19.00   Rectangle 60/45

91.20.00   Obtuse-angled triangle (2 pieces)

91.21.00   Angle model

91.22.00   Plumb line

91.23.00   Protractor

G1-1:Classification of angles
G1-2:Angle measurement
G1-3:A few Greek letters
G1-4:Angles on lines
G1-5:Angles on parallel lines
G1-6:Special triangles
G1-7:Special quadrilaterals
G1-8:Symmetric quadrilaterals
G1-9:The sum of angles in a triangle
G1-10:The theorem of Thales
G1-11:Area measurement
G1-12:The area of a kite
G1-13:The area of a parallelogram
G1-14:The trapezoid and its area
G1-15:The area of a triangle
G1-16:The Pythagorean theorem
G1-17:Euclid’s altitude theorem
G1-18:Euclid’s cathetus theorem
G1-19:The intercept theorem
G1-20:Trigonometric functions in right-angled triangles