Notes for Section 1 4 Measuring Segments and

Notes for Section 1 -4 Measuring Segments and Angles

To measure a segment, we can use a ruler and measure the distance between the two ______. OR We can think of the segment as part of a ______ line. A B C D E F G H I -4 -3 -2 -1 0 1 2 3 4

Look at segment AE The coordinate of A is _______ How can we determine the length of segment AE? | The coordinate of E is _______ |= | |= A B C D E F G H I -4 -3 -2 -1 0 1 2 3 4

Congruent Segments Two segments with the same ____, denoted __ Can you determine some congruent segments from the number line below? A B C D E F G H I -4 -3 -2 -1 0 1 2 3 4

Practice 1 -4 #4 -7

An important postulate……. If three points A, B, and C are _______ and B is between A and C, then ________.

Practice 1 -4 # 1 – 3, 9 - 11

Midpoint A point that divides a segment into two _____ segments. A midpoint _____ the segment.

Let’s look at the following example. Z is the midpoint of segment XY, and XY = 27. Find XZ.

Practice 1 -4 # 21 - 22

Angle Formed by two _____ with the same endpoint, denoted ___ The endpoint is called the _____ of the angle. A 1 B C There are four ways to name this angle. _____________

One way to express the measure of an angle is in _____. 65° B We would write this as…… _______

Angle Measuring Activity

Acute Angle An angle with measurement between ____ and ____ degrees.

Right Angle An angle with measurement of _____ degrees.

Obtuse Angle An angle with measurement between ____ and ___ degrees.

Straight Angle An angle with measurement of ____ degrees.

An important postulate…… If point B is in the ____ of AOC, then _____________ A B O C

Congruent Angles with the same ____. For example… If Then ______, ______

Practice 1 -4 # 8, 12 - 20