Not only the word geometry is a Greek one, but the names of the geometrical shapes are Greek too. Therefore, they are familiar to you. Greek words you already know. Additionally, from the English names of the geometrical shapes which have many corners or sides you can derive the Greek words for some numbers.

The word geometry comes from the Greek γεωμετρία, which is a compound one from γη (γεω = geo) + μέτρο (=meter). It means the science of measuring the earth.

Geometry has been extremely developed in ancient Greece. Complex geometrical theories and calculations were applied in the building of the amphitheaters, the temples and in shipbuilding as well. The Parthenon and the trireme are two examples of the development of geometry in Classical Greece. The Geometry as a science is also called Euclidean Geometry, a term which has been used for 2500 years. In Classical Greece Euclid, Pythagoras, Thales, Plato and Aristotle had experimented and established many of the rules in Geometry, which we still apply today.

GEOMETRY IS A GREEK WORD
English word Greek word Pronunciation
Geometry ηγεωμετρία EE geomeTREEa
Geometrical γεωμετρικός geometriKOS
The earthηγη EE YEE
Meter τομέτρο TO MEtro

GREEK NUMBERS YOU ALREADY KNOW
From the English words of the geometrical shapes you are already familiar with some Greek numbers.
English word Greek word Pronunciation
Trigonometric τριγωνομετρικός trigonometriKOS
Tetrahedron τοτετράεδρον TO teTRAedron
Pentahedron το πεντάεδρον TO peNTAedron
Hexagon τοεξάγωνο TO eXAgono
Heptagon το επτάγωνο TO ePTAgono
Octagon τοοκτάγωνο TO oKTAgono

The Greek word έδρα, found as a suffix, -hedron,in English words like tetrahedron, pentahedron, hexahedron, etc. means in Greek, the side, as well as the residence and the office. Tetra(=4)+hedron, penta(=5)+hedron, hexa (=6)+hedron.So, when we ask: Πούείναιηέδρασου; we mean where is your office? or even your house?ΗέδραμουείναιστηνΑθήνα. = MyresidenceisinAthens.Ηέδραμουείναιστην Αμερική. = Myresidenceisin U.S.
The Greek word γωνία, found as a suffix,-gon, in English words like hexagon, heptagon, octagon, trigonometric etc. means in Greek the corner:hexa(=6)+gon, hepta(=7)+gon, octa(=8)+gon, tri(=3)+gono+metric.
From the names of the geometrical forms we can derive the following numbers in Greek.
3 = ΤρίαTREEa
4 = Τέσσερα TEsera
5 = Πέντε PEnte
6 = Έξι Exi
7 = Επτά ePTA
8 = Οκτώ oKTO

VOCABULARY
Greek word Pronunciation Meaning
Εγώμετράω eYOmeTRAo I measure, I count
Η έδρα EE Edra the side, residence, office
Οιέδρες EE Edres the sides
Η γωνία EE goNEEa the corner
Οιγωνίες EE goNEEes the corners
Με ME with

EXERCISE
Now, can you understand and translate the Greek phrases below? They are all built with Greek words used in English. Youmay use the vocabulary above, and basic verbs έχει = has, έχουν = have and είναι = is.
1.Εγώ μετράω με το μέτρο.
2.Σε ποια γωνία είναι το σπίτι σου;
3. Το τετράεδρο έχει τέσσερις έδρες.
4.Η πυραμίδα έχει πέντε γωνίες.
5. Το οκτάγωνο έχει οκτώ γωνίες.
6. Το εξάγωνο έχει έξι γωνίες.

Try to match the Greek sentences above with the English ones, below.
1. The pyramid has five corners.
2. I measure with the meter.
3. On which corner is your house?
4. The hexagon has six corners.
5. The tetrahedron has four sides.
6. The octagon has eight corners.

PRONUNCIATION KEY
i (idiom), ee (needle), e (energy), o (organism), oo (boot), y (yes), h (helium), th (theory), d (the). The capitalized syllables are accented.