1 / 16

Warm-Up: Billiards (“Pool”)

Warm-Up: Billiards (“Pool”). Who has played pool? What’s a “bank shot”? How do you know where to hit the ball on the side? It’s all in the angles! Angles are the foundation of geometry. 1.4 Angles & their Measures. Objectives: Define: Angle, side, vertex, measure, degree, congruent

miriam-nolan
Télécharger la présentation

Warm-Up: Billiards (“Pool”)

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. Warm-Up: Billiards (“Pool”) • Who has played pool? • What’s a “bank shot”? • How do you know where to hit the ball on • the side? • It’s all in the angles! • Angles are the foundation of geometry

  2. 1.4 Angles & their Measures Objectives: Define: Angle, side, vertex, measure, degree, congruent Name angles with the vertex always in the middle Measure angles with a protractor Identify congruent angles Classify angles as acute, right, obtuse, or straight Add and subtract angle measures using the angle addition postulate

  3. Angle symbol: • 2 rays that share the same endpoint (or initial point) Sides – the rays XY & XZ Vertex – the common endpoint; X Y X 5 Z Named <YXZ, <ZXY (vertex is always in the middle), or <X (if it’s the only <X in the diagram). Angles can also be named by a #. (<5)

  4. In the figure, there are three different <Q’s (two smaller ones and a larger one). therefore, none of them should be called <B. The vertex is ALWAYS in the middle of the name

  5. Example 1: Naming Angles One angle only: < EFG or < GFE Three angles: < ABC or < CBA < CBD or < DBC < ABD or < DBA

  6. Angle Measurement

  7. Postulate 3: Protractor Post. • The rays of an angle can be matched up with real #s (from 1 to 180) on a protractor so that the measure of the < equals the absolute value of the difference of the 2 #s. 55o 20o m<A = 55-20 = 35o

  8. B is ___________ C is ___________ D is ___________ Interior or Exterior? in the interior in the exterior on the < B C D A

  9. Adjacent Angles • 2 angles that share a common vertex & side, but have no common interior parts. (they have the same vertex, but don’t overlap) such as <1 & <2 2 1

  10. Postulate 4:Angle Addition Postulate

  11. Example 2: m < FJH = m < FJG + m < GJH m < FJH = 35° + 60°

  12. Example 3: . If m<QRP=5xo, m<PRS=2xo, & m<QRS=84o, find x. 5x+2x=84 7x=84 x=12 m<QRP=60o m<PRS=24o S P Q R

  13. Acute angle – Right angle – Obtuse angle – Straight angle – Measures between 0o & 90o Measures exactly 90o Measures between 90o & 180o Measures exactly 180o Types of Angles

  14. Example 4: Classifying Angles • A. straight • B. acute • C. obtuse

  15. Name an acute angle <3, <2, <SBT, or <TBC Name an obtuse angle <ABT Name a right angle <1, <ABS, or <SBC Name a straight angle <ABC Example 5: S T 3 1 2 A B C

  16. AssignmentGeneral 1.4 AHonors 1.4 B

More Related