Line

• Two angle whose measures a sum of 90° are called complementary angles
• Two angles whose measures have a sum of 180° are called supplementary angles
• Theorem is a statement that can be proven
• Two angles formed by intersecting lines and facing in the opposite direction called vertical angles
• Transversal is a line that intersects two lines and in the same plane at different points
• Pairs of angles formed by two line and a transversal that make an F pattern called corresponding angles
• Pairs of angles formed by two lines and a transversal that make a C pattern called Same-side interior angles
• Pairs pf angles formed by two line and a transversal that make a Z pattern called Alternate interior angles
• Congruent triangles in which corresponding parts (side and angles) are equal in measure.
• Similar triangles in which corresponding angles are equal in measure and corresponding sides are proportion (ratios equal).
• Angle bisector is a ray that begins at the vertex of an angles of equal and divide the angle into two angles of equal measure.
• Segment bisector is a ray, line or segment that divides a segment into two parts of equal measure.
• The side of equal measures is an isosceles triangle (legs of an isosceles triangle)
• The third side of an isosceles triangle

  Base of an isosceles triangle
• Having angles that are all equal in measure called Equiangular
• A line that bisects a segment and is perpendicular to it

  Perpendicular bisector
• A segment from a vertex of a triangle perpendicular to the line containing the opposite side.

  Altitude
• For any angle, the measure of the whole is equal to the sum of the measures of it's non-overlapping parts

  Angle addition postulate