Intro to Geometry

Geometry- the study of lines, 2d shapes, and 3d shapes

The basics- lines, planes, rays, points

• Lines that continue forever both ways

• Line segments are parts of a line connected by two points

• Planes are 2d objects that have no thickness and extend forever

• Rays are pieces of lines that start with one point and go in one direction forever

Types of angles

• Complementary = 90 degrees

• Supplementary = 180 degrees (flat line)

• acute angle = <90 degrees

• obtuse angle = >90 degrees

• right angle = 90 degrees

  

• Alternate interior and alternate exterior angles are always congruent you just need two parallel lines with a transversal 90 degrees

• Same-side interior and same-side exterior angles lie on the same side of the transversal 180 degrees

• Corresponding angles are congruent they are on the same side as the transversal 90 degrees

• Vertical angles are opposite of each other 90 degrees