1 / 16

Section 1-4

Section 1-4. Angles. Angle – figure formed by 2 rays that have the same endpoint. The rays are the _______. The common endpoint is the _________. When naming an angle, use __ letters, __ letter, or ___ number. Vertex = ______ Name the angle. Sides = ____ and ____. sides. vertex.

ross-barton
Download Presentation

Section 1-4

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. Section 1-4 Angles

  2. Angle – figure formed by 2 rays that have the same endpoint. The rays are the _______. The common endpoint is the _________. When naming an angle, use __ letters, __ letter, or ___ number. Vertex = ______ Name the angle. Sides = ____ and ____ sides vertex 3 1 1 point B ABC, CBA, 4, B

  3. DBC, ABC ABD, Name 3 angles.

  4. degrees right acute Angles are measured in _________. There are 4 classifications of angles. _______________ _______________ Measures between Measure _______ _____ and _____ ________________ _______________ Measures between Measure _______ ______ and _______ 90° 90° 0° obtuse straight 180° 90° 180°

  5. Protractor Postulate: Given QOP, if is paired with x and is paired with y, then mQOP = . Example 1 20° and 90° Example 2 90° and 120° Example 3 90° and 40° = 70° = 30° = 50°

  6. Angle Addition Postulate: If point B lies in the interior of AOC, then mAOB + mBOC = mAOC. Angle Addition Postulate: If AOC is a straight angle, then mAOB + mBOC = 180°.

  7. Find x, mABC, mCBD. mABC = (7x)° mABC = 7(20) mABC = 140° mCBD = (2x)° Angle Addition Postulate mCBD = 2(20) mABC + mCBD = mABD mCBD = 40° 7x + 2x = 180 9x = 180 x = 20

  8. Find x and the other angle measures. (3x + 4)° 3(18) + 4 58° Angle Addition Postulate (2x – 4)° 2(18) – 4 (3x + 4) + (2x – 4) = 90 3x + 4 + 2x – 4 = 90 32° 5x = 90 x = 18

  9. equal measures congruent angles – angles that have ____________ _______________ adjacent angles – 2 angles in a _______ that have a _________ ________ and a _________ ______, but no common interior points plane common common vertex side nonadjacent adjacent nonadjacent adjacent nonadjacent

  10. ray congruent bisector of an angle – a ______ that divides an angle into 2 _____________ angles Ex. Given: bisects BED, mAEB = (19x)°, mBEC = (8x + 20)° Find x and mCED. (19x) + (8x + 20) + (8x + 20) = 180 19x + 8x + 20 + 8x + 20 = 180 35x + 40 = 180 35x = 140 (8x + 20)° x = 4 (8x + 20)° (19x)° mCED = (8x + 20)° mCED = 8(4) + 20 mCED = 52°

  11. Examples: Give another name for each angle. 1. DEB 2. CBE 3. BEA 4. DAB 5. 7 6. 9 8 3 1 C, ABE DCB, ECB, DCA, ECA

  12. EAB AEC 7. m1 + m2 = m______ 8. m3 + m4 = m______ 9. m5 + m6 = m______ or ______ EDC 180°

  13. point B 8 or BED 10. Name the vertex of 3. 11. Name the right angle.

  14. A or BAE State another name for each angle. 12. 1 13. 6 14. EBD 15. 4 BDC 3 DBC

  15. 7 ABE 16. BDE or BDA 17. 2 18. 5 19. 9 C or BCD BEA

  16. HOMEWORK: page 21 #2-34 even

More Related