1.2: Measurement of Segments & Angles

I can classify angles by size I can recognize congruent angles and segments Construct segments and angles 1.2: Measurement of Segments & Angles Draw & label what you think the following would look like: Acute Angle Obtuse Angle Right Angle Straight Angle Day 2

NOTATION: You will need to know how to read/use the following: • AB, means segment AB (has a length) • AB, means line AB (impossible to measure) • AB, means ray AB (impossible to measure) • AB, means length of segment AB • ∡ symbol for angle • ∡s symbol for angles • ⁰ symbol for degrees • m ∡ A means “the measure of angle A” • congruent, ≇ not congruent

Classification of Angles • Acute angle - any angle whose measure is greater than 0⁰ and less than 90⁰ • Right Angle – any angle whose measure is exactly 90⁰ A• Between 0 and 90! B• C• A• Exactly 90! B• C•

Classification of Angles • Obtuse Angle – any angle whose measure is greater than 90⁰ but less than 180⁰ • Straight Angle – any angle whose measure is exactly 180⁰ Between 90 and 180! B • C• A • Exactly 180! A• B• C•

B• A• C• Congruent Angles and Segments – angles/segments that have the same measure/length • In the diagram below, ∡s A, B, and C are congruent. We write ∡A  ∡B  ∡C In the diagram above, segments AB, CD, and EF are congruent. We write AB  CD  EF. A• B• C• F• 3 centimeters E• 3 centimeters D• 3 centimeters

D• Congruent Angles and Segments • Often, we use identical tick marks to indicate congruent angles and segments. In the following diagram, the identical tick marks indicate that there are four pairs of congruent parts. Can you name them? A• B• G• H• C• F• E• K• J•

Constructions: Copying a Segment • Constructing a Segment

Constructions: Copying an Angle • Constructing an Angle

1.2: Measurement of Segments & Angles