Problems from Angles: type of angles, measure and operations

Are the following affirmations true?

  1. An angle is the point where two lines intersect, also called a vertex.
  2. The angles of $$90$$ degrees are straight angles.
  3. A full angle is two straight angles.
  4. $$90^\circ+ 90^\circ+ 90^\circ+ 90^\circ+ 90^\circ = 90^\circ$$
  5. $$-90^\circ-90^\circ-90^\circ-90^\circ-90^\circ = 90^\circ$$
  6. If we do the bisector angle of the bisector angle of a given angle we obtain a quarter of the original angle.
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Development:

  1. An angle is the aperture formed by two straight lines, not the intersection point.
  2. The angles of $$90$$ degrees are called right angles. Straight angles are $$180$$ degrees.
  3. A straight angle is one of $$180^\circ$$. If we add two of them together we obtain $$360^\circ$$, which is a full angle.
  4. $$90^\circ+ 90^\circ+ 90^\circ+ 90^\circ+ 90^\circ = 450^\circ = 90^\circ$$
  5. $$-90^\circ-90^\circ-90^\circ-90^\circ-90^\circ = -450^\circ = -90^\circ$$
  6. The bisector angle divides the angle in $$2$$ parts. If we calculate the bisector angle twice (in other words, the bisector of the bisector angle), we will get an angle that is a quater of the original.

Solution:

  1. False
  2. False
  3. True
  4. True
  5. False
  6. True
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