Do Now 4/2/13 Take out HW from last night. Take out HW from last night. Text p. 312, #1-16 all, 21 Text p. 312, #1-16 all, 21 Copy HW in your planner. Copy HW in your planner. Text p. 318, #10-23 all, 27 & 28 Text p. 318, #10-23 all, 27 & 28 In your journal, describe how to use a protractor. Use step-by-step instructions on how to measure an angle. In your journal, describe how to use a protractor. Use step-by-step instructions on how to measure an angle.

Homework Text p. 312, #1-16 all, 21 1) Q, R, S 1) Q, R, S 2) 2) 3) plane QRS 3) plane QRS 4) 4) 5) 5) 6) 6) 7) D, E, F 7) D, E, F 8) 8) 9) plane DEF 9) plane DEF 10) 11) 12) 13) Plane ABC contains points A, B, C; lines AB & BC; line segments AB, AC, & BC; rays AB, BA, BC, CB, & CA. Plane ACD contains points A, C, D; line segments AC, AD, & CD; and ray CA

Homework Text p. 312, #1-16 all, 21 14) 6; 14) 6; 15) answer vary 15) answer vary 16) 16) 21) C 21) C

Objective SWBAT identify angles and angle pairs SWBAT identify angles and angle pairs

Angle two rays with a common endpoint. C D E Vertex Sides Section 8.2 “Classifying Angles”

Naming Angles The following angle can be named in three ways: The following angle can be named in three ways: B C A Vertex

Types of Angles Right angle = 90 degrees Acute angle = less than 90 degrees Obtuse angle = more than 90 degrees Straight angle = exactly 180 degrees

The MEASURE of is written as. The MEASURE of is written as. A PROTRACTOR can be used to approximate the measure of an angle. A PROTRACTOR can be used to approximate the measure of an angle.

Using a Protractor Find Find B A C = 130°

Using a Protractor Find Find B A C = 70°

What is the measure of a straight line (in degrees)? CA 180° B

Angles Supplementary Angles When two angles form a straight line, the sum of their measures is 180° C D E A 180° 150° 30°

Complementary Angles When two angles form a right angle, the sum of their measures is 90° Y Z X W 64° 26° 90°

Use the diagram to tell whether the angles are complementary, supplementary, or neither. OMP and PMQ O N P Q R M 60° 30°  OMP = 60° and  PMQ = 30° and 30°+60° = 90° therefore, they are complementary.

Use the diagram to tell whether the angles are complementary, supplementary, or neither.  NMO = 15° and  OMR= 165° and 15°+165° = 180° therefore, they are supplementary. O N P Q R M NMO and OMR 15° 165°

Use the diagram to tell whether the angles are complementary, supplementary, or neither.  BAC = 35° and  EAF= 35° and 35°+35° = 70° therefore, they are neither. C B D E F A 35° 35° BAC and EAF

Finding Angle Measures Angles A and B are complementary. If mA is 56 °, what is the mB? Since A and B are complementary, mA + mB = 90 °. mA + mB = 90 ° 56 ° + mB = 90 ° – 56 ° mB = 34 ° Substitute 56° for mA. Subtract 56° from both sides. The measure of B = 34 °.

Finding Angle Measures Angles P and Q are supplementary. If mP is 32 °, what is the mQ? Since P and Q are supplementary, mP + mQ = 180 °. mP + mQ = 180 ° 32 ° + mQ = 180 ° – 32 ° mQ = 148 ° Substitute 32° for mP. Subtract 32° from both sides.. The measure of Q = 148 °.

Homework Text p. 318, #10-23 all, 27 & 28 Text p. 318, #10-23 all, 27 & 28