In basic Euclidean geometry no, the sum of the angles always equals 180 degrees exactly. In non-Euclidean geometry it can exceed 180 degrees.
A postulate.
Geometry, unlike science, doesn't really have laws, it has theorems, and many different mathematicians contributed to the creation of the basic theorems of geometry. Perhaps the best known is Pythagoras.
undefying end!
point, line,
no, its a postulate
In basic Euclidean geometry no, the sum of the angles always equals 180 degrees exactly. In non-Euclidean geometry it can exceed 180 degrees.
compass and straightedge
It is a very basic concept which cannot be defined. Undefined terms are used to define other concepts. In Euclidean geometry, for example, point, line and plane are not defined.
an equation
The basic shape with 3 sides and 3 corners is called a triangle. A triangle is a polygon with three straight sides and three angles. It is the simplest polygon in Euclidean geometry.
A postulate.
Yes, you can move from basic Algebra to Geometry, but only upon recommendation from your teacher.
Euclid
The answer depends on what the requirements for the basic construction are.
Geometry, unlike science, doesn't really have laws, it has theorems, and many different mathematicians contributed to the creation of the basic theorems of geometry. Perhaps the best known is Pythagoras.
The five basic postulates of Geometry, also referred to as Euclid's postulates are the following: 1.) A straight line segment can be drawn joining any two points. 2.) Any straight line segment can be extended indefinitely in a straight line. 3.) Given any straight line segment, a circle can be drawn having the segment as a radius and one endpoint as the center. 4.) All right angles are congruent. 5.) If two lines are drawn which intersect a third in such a way that the sum of the inner angles on one side is less than two right angles (or 180 degrees), then the two lines inevitably must intersect each other on that side if extended far enough. (This postulate is equivalent to what is known as the parallel postulate.)