Over Lesson 1 3 Measure and classify angles

Over Lesson 1– 3 • Measure and classify angles. • Identify and use congruent angles and the bisector of an angle.

Content Standards G. CO. 1 Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment, based on the undefined notions of point, line, distance along a line, and distance around a circular arc. G. CO. 12 Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc. ). Mathematical Practices 5 Use appropriate tools strategically. 6 Attend to precision.

You measured line segments. • Measure and classify angles. • Identify and use congruent angles and the bisector of an angle.

• ray • degree • opposite rays • right angle • acute angle • side • obtuse angle • vertex • angle bisector • interior • exterior

Angles and Their Parts A. Name all angles that have B as a vertex. Answer:

Angles and Their Parts B. Name the sides of 5. Answer:

Angles and Their Parts C.

B. A. B. C. D. none of these

Measure and Classify Angles A. Measure TYV and classify it as right, acute, or obtuse. Answer: m TYV = 90, so TYV is a right angle.

Measure and Classify Angles Answer: 180 > m WYT > 90, so WYT is an obtuse angle.

Measure and Classify Angles

A. Measure CZD and classify it as right, acute, or obtuse. A. 30°, acute B. 30°, obtuse C. 150°, acute D. 150°, obtuse

C. Measure DZX and classify it as right, acute, or obtuse. A. 30°, acute B. 30°, obtuse C. 150°, acute D. 150°, obtuse

Measure and Classify Angles INTERIOR DESIGN Wall stickers of standard shapes are often used to provide a stimulating environment for a young child’s room. A five-pointed star sticker is shown with vertices labeled. Find m GBH and m HCI if GBH HCI, m GBH = 2 x + 5, and m HCI = 3 x – 10.

Measure and Classify Angles Step 1 Solve for x. GBH HCI m GBH = m HCI 2 x + 5 = 3 x – 10 2 x + 15 = 3 x 15 = x Given Definition of congruent angles Substitution Add 10 to each side. Subtract 2 x from each side.

Measure and Classify Angles Step 2 Use the value of x to find the measure of either angle. . Answer: m GBH = 35, m HCI = 35

Find m BHC and m DJE if BHC DJE, m BHC = 4 x + 5, and m DJE = 3 x + 30. A. m BHC = 105, m DJE = 105 B. m BHC = 35, m DJE = 35 C. m BHC = 35, m DJE = 105 D. m BHC = 105, m DJE = 35

Homework Page 41 (12 -36) / Page 42 (37 -42)