Complementary Angles :
Complementary Angles If the sum of the measures of two angles is exactly 90º then the angles are complementary.
Supplementary Angles :
Supplementary Angles If the sum of the measures of two angles is exactly 180º then the angles are supplementary.
Vertical Angles :
Vertical Angles Vertical angles are formed by two intersecting lines. They are the angles that are opposite each other. Vertical angles are congruent (they have equal measures). In this picture, <1 and <3 are vertical angles. What is the measure of <2? <2 is 120º because it is congruent to the vertical angle across from it.
Transversals :
Transversals A transversal crosses two or more lines at different points:
Interior angles are on either side of a transversal between a pair of lines.
Exterior angles are on either side of a transversal outside of a pair of lines. Angles 3,4,5, and 6 are interior angles. Angles 1,2,7, and 8 are exterior angles.
Homework Time! :
Homework Time!