NCERT Solutions for Chapter: Introduction to Euclid's Geometry, Exercise 2: Exercise

The boundaries of the solids are curves.

The edges of a surface are curves.

The things which are double of the same thing are equal to one another.

If a quantity $B$ is a part of another quantity $A$, then $A$ can be written as the sum of $B$ and some third quantity $C$.

The statements that are proved are called axioms.

“For every line $l$ and for every point $P$ not lying on a given line $l$, there exists a unique line $m$ passing through $P$ and parallel to $l$” is known as Playfair’s axiom.

Two distinct intersecting lines cannot be parallel to the same line.

Attempts to prove Euclid’s fifth postulate using the other postulates and axioms led to the discovery of several other geometries.