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Big Ideas Math Integrated I, 2016

BI

Big Ideas Math Integrated I, 2016 View details

5. Measuring and Constructing Angles

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Exercise 1 Page 414

The symbol ∠ is used to name an angle.

∠ Q
∠ PQR
∠ RQP

Practice makes perfect

Let's begin by recalling some basic geometric definitions.

Concept	Definition
Angle	Set of points consisting of 2 different rays that have the same endpoint.
Vertex of an Angle	The common endpoint of the 2 rays that form an angle.
Sides of an Angle	The rays that form an angle.

Now, whenever we want to name an angle, we use the symbol ∠. Each angle can be named in several ways. One way to name an angle is to use the letter or number that corresponds to the vertex of the angle. In this case, it is ∠ Q.

Alternatively, we can place the letter name of the vertex between the name of points that lie on the rays creating the angle. We can do this in two ways by interchanging the names of the points. Here, we have P and R. ∠ P Q R or ∠ R Q P

Subchapter links

Communicate Your Answer p.413

Monitoring Progress p.414-418

Exercises p.419-422