1 / 19

1.3 Measuring Angles

1.3 Measuring Angles. Objectives: Measure angles with a protractor Identify and use the angle addition postulate. Warm-Up: Find the indicated value. AC = 20; AB = _____. A. B. C. x-4. 2x+3. Vocabulary:. Degree:. The most common unit of angle measure.

hasad-barnett
Download Presentation

1.3 Measuring 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. 1.3 Measuring Angles Objectives: Measure angles with a protractor Identify and use the angle addition postulate Warm-Up: Find the indicated value. AC = 20; AB = _____ A B C x-4 2x+3

  2. Vocabulary: Degree: The most common unit of angle measure. (this is the unit of measure that results when a half circle is divided into 180 equal parts)

  3. Vocabulary: Protractor: A geometric ruler that is a half-circle with coordinates from 0oto 180o.

  4. Vocabulary: Measure of an Angles: m<AVB is |a – b| or |b – a| B A V

  5. Vocabulary: Complementary Angles: Two angles whose measures have a sum of 90o (each angle is called the compliment of the other) 67⁰ 60⁰ 23⁰ 30⁰

  6. Vocabulary: Supplementary Angles: Two angles whose measures have a sum of 180o (each angle is called the supplement of the other) 43⁰ 137⁰

  7. Vocabulary: Linear Pair: When the endpoint of a ray falls on a line so that two angles are formed, then the angles are known as a linear pair. 2 1 Linear Pair Property: If two angles form a linear pair they are supplementary.

  8. Vocabulary: Angle Congruence Postulate: If two angles have the same measure then they are congruent. If two angles are congruent then they have the same measure.

  9. Types of Angles: An angle whose measure is 90⁰ Right Angle: Acute Angle: An angle whose measure is less than 90⁰ An angle whose measure is greater than 90⁰ and less than 180⁰ Obtuse Angle:

  10. Vocabulary: Angle Addition Postulate: If point S is in the interior of <PQR the m < PQS + m < SQR = m < PQR S P R Q

  11. Example 1: Measure of an Angles: m<AVB is |a – b| or |b – a| m < BAC = ______ m < CAD = ______ m < BAD = ______ B C D A

  12. Example 2: Identify the Congruent Angles. A B D C

  13. Example 3: Name all the complementary and supplementary angle pairs. Complementary angles: ____ & _____ Supplementary angles: ____ & _____ 30o B 60o A 120o C

  14. Collins Writing Type 1: In creating a protractor, does the size of the half-circle make a difference?

  15. Example 4: Find the missing angle measures. m < BTE = 40⁰, m <ETM = 60⁰, m <BTM = ______ m < BTE = 112⁰, m <ETM = ______, m <BTM = 168⁰ m < BTE = ______, m <ETM = 47⁰, m <BTM = 92⁰ E B M T

  16. Example 5: m <XTY = 42⁰ and< WTX and <XTZ form a linear pair. Find the following: m < YTZ = ______ m <WTX = ______ m <WTY = ______ m <XTZ = ______ X Y W T Z

  17. Example 6: m < DSF = (45 + x)⁰, find the value of x and then give each indicated angle measure. m < DSF : m <DSE : m <ESF : D E (5x+4)⁰ S (4x+1)⁰ F

  18. Example 7: m < BAD = 82⁰& m <CAE = 64⁰ find: m < 1 : m <2 : m <3 : m <4 : m <BAF: B C 1 D 2 A 3 E 4 F

  19. Homework: pages 30-32 (21 problems) #’s 13-19, 27-34, 36-38, 42-44

More Related