Ch 1.6Standard 13.0:

Students prove relationships between angles by using properties of complementary,

supplementary, and vertical angles.

Objective:1) To find the measures of angles.2) To identify special angle pairs.

Key Definitions

Postulate

More Key Definitions

A. complement of F

B. supplement of G

90 – 59 = 31

(180 – x)

180 – (7x+10) = 180 – 7x – 10

= (170 – 7x)

(90 – x)

Example 1Find the measure of each of the following.

a. complement of E

Find the measure of each of the following.

b. supplement of F

= (102 – 7x)°

180 – 116.5° =

90° – (7x – 12)° = 90° – 7x° + 12°

(90 – x)°

(180 – x)

Example 2

are two nonadjacent angles formed by two intersecting lines whose sides form two pairs of opposite rays.

Still More Key DefinitionsVertical angles

1 and 3 are vertical angles, as are 2 and 4.

Congruent angles are angles that have the same measure.Arc marks are used to show that the two angles are congruent.

Please click on the following link (or copy & paste into your browser) to access an interactive activity pertaining to congruent triangles and complementary and supplementary angles.

http://glencoe.com/sites/common_assets/mathematics/nat_geo_2010/animation/cogeo_ch04/course_player.html

Activity