Geometry Notes

The Language of Geometry Point: A point is a specific location in space but the point has no size or shape Line: a collection of points that extends indefinitely in two directions Arrowheads: These are used to show that a line has no endpoints Line Segment: This is a part of a line containing two endpoints and all points between the points Plane: This is a flat surface that has no boundaries. A plane can be named by any 3 points of the plane but they must not be on the same line Ray: A ray extends from one point indefinitely in one direction. It is named by using the endpoint first then another point on the line

More Language of Geometry Angle: This is formed by two rays with a common endpoint point Vertext: The common endpoint of an Angle Degree: a circle can be separated into 360 arcs of the same length. The total is 360. An angle has a measurement of one degree if its vertex is at the center of the circle and its sides contain the endpoints of one of the 360 equal arcs

More Language of Geometry Protractor: Used to measure angles Acute: Angles measuring more than 0 and less than 90 degrees Right: 90 degree angles Obtuse: Angles measuring greater than 90 but less than 180 degrees

More Language of Geometry Circle Graph: Compares and shows parts of a whole –Ex. Pie Charts Vertical Angles: Angles opposite to one another >< Congruent: Angles that have the same measure Perpendicular: If the vertical angles formed by two intersecting line are right angles, the lines are perpendicular + Adjacent Angles: Angles with a common side Complementary: The sum of their measures is 90 degrees Supplementary: The sum of their measures if 180 degrees

More Language of Geometry Parallel Lines: Two or more lines in a plane that do not intersect. They are always the same distance apart Transversal: A line intersects two parallel lines and eight angles are formed Interior Angles: Angles created inside the parallel lines Exterior Angles: Created outside the lines

Radius, Circumference & Diameter Diameter: The distance across a circle through the center –Diameter = 2R Radius: The distance from the center of a circle to any point on the circle –Measure the widest part of the circle to get the diameter, then divide by 2 to get the radius Circumference: The distance around any circle –Circumference = π D Circumference/Diameter = π π =3.142