1) straight angle because it is completely flat, has no inclination and measures 180 °
2)circular arc, because from a to any point of the circle there is the same measure
3)inscribed angle, because that is what angles within a circle are called, which do not have their vertex in the middle of the circle
4)Chord , because is a segment inside the circle
5)Secant, because is a infinite line that cuts the circle at two points
6)complementary angles, because the sum of these two angles gives a right angle(90°)
7) Acute angle, because its measurement is less than 90 °
8) Vertical angles, when two lines intersect, the angles opposite the vertex are equal