What is an angle in Geometry?

Question

Geometry- Angles

Answer 1

In Geometry we use term "ray" to define an angle.
Ray is a line with the start point but no end point.
Angle is the figure formed by two rays with the common start point, called the vertex of the angle.
               /
        A   / 
           / 
         / 
   B  /                           
                             C 

Names of given angle are:
  /   ABC  or  /   CBA  or  /   B  

Answer 2

an angle is the conjoining point between two intersecting lines. these can be measured in degrees or radians. for example, a triangle ("tri- angle") has three angles, with all three adding up to 180 degrees. a square/rectangle has four angles, all of which are 90 degrees. 

/_ this is an acute angle, it is smaller than 90 degrees

|_ this is a right angle, it is 90 degrees

\_ this is an obtuse angle, it is greater than 90 degrees