Topic 1-5 Angle Relationships

ANGLES An angle is a set of points consisting of two rays, with a common endpoint called THE VERTEX of the angle. The rays are callled SIDES or LEGS of the angle An angle can be classified according its measurement: Acute angle: Measure between 0 to 90 degrees Right angle: Measure 90 degrees Obtuse angle: Measure between 90 to180 degrees Straight angle: Measure 180 degrees Reflex angle: Measure between180 to 360 degrees

ANGLES In addition, an angle can be classified according its characteristics and relationship: Adjacent angles: They have the same vertex and a common side, but they don’t share any interior point. Linear pair angles: Two adjacent angles which sum 180 degrees

ANGLES Vertical angles: Are the opposite pair of angles formed when two lines intersect. They are always congruent Complementary angles: Angles adjacents or not, which sum 90 degrees

ANGLES Supplementary angles: Are angles which sum is 180 degrees

Congruents angles ANGLES Angles between parallel lines crossed by a transversal -) Co-interior angles: 2-5, 3-8 -) Co-exterior angles: 1-6, 4-7 -) Vertical angles: 1-3, 2-4, 5-7, 6-8 -) Corresponding angles: 1-5, 2-6, 4-8, 3-7 -) Alternate interior angles: 2-8, 3-5 -) Alternate exterior angles: 1-7, 4-6 Congruents angles