1 / 13

1.2 Measurement of Segments and Angles

Learn to measure segments in both U.S. customary units and the metric system. Understand angle measurement using degrees and radians. Classify angles by size and identify congruent angles and segments. Practice calculating angle measurements and explore unique angle scenarios such as clock hands at 5:15.

clementj
Download Presentation

1.2 Measurement of Segments and Angles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 1.2 Measurement of Segments and Angles

  2. Measuring Segments Match item being measured with proper unit. U.S.: Inches, feet, yards, miles etc. Metric: km, cm, m, mm

  3. Distance: absolute value A B m AB cm 1 2 3 4 |2-3| or |3-2| = |-1| = |1| = 1 = 1 The length of AB = 1 cm

  4. Measuring angles: Tool: protractor Unit of measure: Degrees Radians Grads

  5. Angle measurement Angle measurement is the opening from one ray to the next ray. We usually use the inside measurement, 180° or less. A full turn is a circle and measures 360°.

  6. Angle measurement m<PAR = 90 P  m<A = 90 A R 1 m<1 = 135

  7. Classify angles by size Acute: 0<x<90 Right: 90 Obtuse: 90<x<180 Straight: 180

  8. Parts of a degree: 1 Degree = 60’ (minutes) 1 Minute = 60” (seconds) So, 87  = 8730’ 90 = 8959’60”

  9. Find m<CBD m<ABD = 90 C A m<ABC = 7421’10” B D 90 - 7421’ 10” 8959’ 60” - 7421’ 10” 1538’50”

  10. Congruent angles and segments Symbol: = = < have the same measure have the same length = A 60 B 60 <A = <B

  11. Congruency Tick marks show congruency X A B Z Y C Name congruent angles and segments.

  12. Example A B m<ABC = 90 m<1 = (3x+4) m<2 = (x+6) 1 2 Find both angles! C 3x + 4 + x + 6 = 90 4x + 10 = 90 4x = 80 x = 20 m<1 = 64° m<2 = 26°

  13. Find the measure of the angle formed by the hands of a clock at 5:15. • The hour hand is on 5 only when the minute hand is on 12. • How far will the hour hand be away from 5 when it is 5:15? • It will be ¼ of the way between the 5 and the 6. • How many degrees is that? • There are 360º in the clock. Every 5 minutes has how many degrees? • ¼ of 30 is • How many “5 minute” intervals do you need to add to that? • The angle measure of 5:15 is 67.5º. 30º 7.5º 2 intervals for a total of 60º.

More Related