you are here > Class Notes - Chapter 1 - Lesson 1-2

Printable version

Measurement of Segments and Angles - Lesson 1-2

Hello, we all got our "tools of geometry!"  That would be that thing I gave you that has a straight edge (for measuring segments), a protractor (for measuring angles), and a compass (for constructing circles and arcs of circles).  We then practiced using the various parts of this tool to measure segments and angles.  You should remember the following, paying particular attention to the symbology!


The measure of an angle


We then discussed how we classify angles by their measure:

An Acute Angle

A Right Angle

An Obtuse Angle

A Straight Angle


At this point, we moved on to some new material...something you didn't do in 4th grade!  It had to do with how we measure angles to a degree of accuracy better than degrees:

Parts of a Degree


We also discussed how to convert from fractional degrees to degrees, minutes, and seconds form and vice versa.  Make sure you can do these types of problems for the quiz and test!!

Fractional degrees to degrees / minutes / seconds


Degrees / Minutes / Seconds to fractional degrees


We also learned how to add and subtract angle measures in degrees, minutes, and seconds form.  Here’s an example:

Subtracting angles in D/M/S form


We ended by learning the definitions for congruent segments and congruent angles and learning what symbols to use in association with them:

Congruent Segments

Congruent Angles

Other Links
Class Notes
Lesson 1-1
Lesson 1-2
Lesson 1-3
Lesson 1-4
Lesson 1-5
Lesson 1-6
Lesson 1-7
Lesson 1-8
Lesson 1-9
Test Topics
If you have questions, email me at