Any idea what does Geometry mean? This word is actually derived from the Greek word ‘geometron’. Here, ‘geometron’ is actually made of two words – Geo and Metron. So geometry is the mathematical study of all shapes and figures. In this following chapter let us study in detail about three dimensional geometry.

**FAQ on Introduction to Three Dimensional Geometry**

**Question 1: What is meant by 3 dimensional?**

**Answer:** In geometry, we can define a three-dimensional shape as a solid figure or an object or shape having three dimensions. They are length, width and height. Always remember that unlike two-dimensional shapes, three-dimensional shapes consist of thickness or depth.

**Question 2: Who invented 3d geometry?**

**Answer:** Euclid of Alexandria, who is said to be a student at the Academy by Plato was the one who wrote a treatise in 13 books (chapters). He named it ‘The Elements of Geometry’, in which he presented geometry in an ideal axiomatic form that we now know as Euclidean geometry.

**Question 3: What are the first 3 dimensions?**

**Answer:** By convention, the first three dimensions are said to be space dimensions x-y-z. Consequently, they are width, height, and depth. The first few dimensions are quite simple to understand, looking at the Zero-Dimension, we see there is only one point, no length, height or depth.

**Question 4: What is a 3-dimensional coordinate system?**

**Answer:** A three-dimensional Cartesian coordinate system forms by a point which we call the origin that denotes by O and a basis that consists of 3 mutually perpendicular vectors. We determine the coordinates of any point in space by three real numbers: x, y, and z.