Geometry

• Point - represented by a dot
• Line - extends indefinitely in two directions
• Segment - part of the line with two endpoints.
• Ray - a line with only one endpoint.
• Difference between a line and a line segment?

  Line has an arrow at the end while line segment has a closed circle at the end.
• Angles - two different rays that have the same initial point.
• Congruent angles - angles that have the same measure.
• Adjacent angles - two angles that share a common vertex
• Degree - commonly used to measure the size of an angle.
• Radian - ratio of the length f an arc to its radius
• Identify the following parts

  A) symbol that symbolizes an angle

  B) length of an arc to its radius

  C) from one point to the center of a circle

  D) one point to one point inside the circle

  
• Types of Angle

  • Straight (180 degrees)
  • Acute(between 0 and 90)
  • Right (exactly 90)
  • Obtuse ( between 90 and 180)
  • Reflex (between 180 and 360)
• Midpoint of a segment- int that divides (or bisect) a segment into two congruent segment

  
• Segment Bisector - a segment, ray, line, or plane hat intersects a segment at its midpoint.

  
• Angle Bisector - a ray that divides an angle into two congruent adjacent angles.

  
• Intersecting lines - lines that intersect at a point.
• Parallel line - two lines in the same plane which will never intersect.
• Skew line - lines that are never parallel and do not intersect.
• Plane - can be considered a flat surface with no thickness extending infinitely in all directions.
• Determining a plane:

  • 3 noncollinear plane
  • 2 intersecting line
  • 2 parallel line
• Space - 3 dimensional expanse hat has length, width, and height.
• True or False

  Collinear points are also coplanar.

  Answer: TRUE
• Vertical angles - two angles formed by intersecting lines located opposite each other.

  
• Linear pair - two adjacent angles are liner if their non-common side are opposite rays

  
• Complementary angles - two angles are complementary angles if the sum of their measures is 90 degrees.

  
• Supplementary angles - two angles are supplementary if the sum of their measures is 180 degrees.
• Transversal - a line that intersects two or more coplanar lines at different points.
• Corresponding angles - when one transversal cuts through two parallel lines, there will be four pairs of corresponding angles.
• Alternate interior angles - when one transversal cuts through two parallel lines, there will be two alternate interior angles.
• When two parallel lines are cut by a transversal How many acute and obtuse angles were formed?

  4 acute and 4 obtuse
• True or False

  If the lines are parallel and cut by a transversal, the corresponding angles are not congruent.

  Answer: False
• True or False

  If the lines are parallel and cut by a transversal, alternate interior angle are congruent.

  Answer: True
• Alternate Exterior Angle - angles that lie outside the two lines on the opposite side of the transversal.
• Consecutive Interior Angle - angles that lie between two lines on the same side of the transversal.
• True or False

  If the lines are parallel and cut by a transversal, the consecutive interior angles are supplementary.

  Answer: True
• Same side Exterior Angles - angles that lie outside the two lines in the same side of the transversal.
• Polygon - a closed plane figure formed by three or more segments.
• Types of General Polygon

  • Triangle (3) (180 degrees)
  • Quadrilateral (4) (360 degrees)
  • Pentagon (5) (540 degrees)
  • Hexagon (6) (720 degrees)
  • Heptagon(7) (900 degrees)
  • Octagon (8) (1080 degrees)
  • Nonagon (9) (1260 degrees)
  • Decagon (10) (1440 degrees)
• Equilateral polygon - a polygon where all sides are equal.
• Equiangular polygon - a polygon here all interior angles are equal.