1.3: Angles - Angles and Rays

1.3: Angles- Angles and Rays GSE M(G&M)–10–2 Makes and defends conjectures, constructs geometric arguments, uses geometric properties, or uses theorems to solve problems involving angles, lines

Rays • A ray extends forever in one direction • Has one endpoint • The endpoint is used first when naming the ray B B B B ray RB R R R R R T ray WT W

Name the 3 rays in the diagram

Angles • Angles are formed by 2 non-collinear rays • The sides of the angle are the two rays • The vertex is where the two rays meet Vertex- where they met ray ray

Angles (cont.) • Measured in degrees • Congruent angles have the same measure

Naming an Angle You can name an angle by specifying three points: two on the rays and one at the vertex. • The angle below may be specified as angle ABC or ABC. The vertex point is always given in the middle. • Named: • Angle ABC • Angle CBA • Angle B * *you can only use the • vertex if there is ONE • angle Vertex

Ex. of naming an angle • Name the vertex and sides of 4, and give all possible names for 4. T Vertex: Sides: Names: X XW & XT WXT TXW 4 4 5 W X Z

Name the angle identified by the

Name the angle shown as

Angles can be classified by their measures • Right Angles – 90 degrees • Acute Angles – less than 90 degrees • Obtuse Angles – more than 90, less than 180

assignments

1.3: Angles - Angles and Rays